What are the optimal thyroid hormone levels. How does TSH regulate thyroid function. What factors can affect thyroid hormone production. When should you be concerned about your thyroid levels.

The Importance of Thyroid Hormones in Body Function

Thyroid hormones play a crucial role in regulating various bodily functions. These hormones, produced by the butterfly-shaped thyroid gland located at the base of the neck, are essential for maintaining optimal health. They influence metabolism, heart function, digestion, muscle strength, brain development, and bone health.

There are three main thyroid hormones:

• T4 (thyroxine): The primary hormone produced by the thyroid gland, which is inactive and serves as a precursor to T3.
• T3 (triiodothyronine): The active form of thyroid hormone that regulates metabolism and other vital functions.
• Calcitonin: A less prominent hormone that helps regulate calcium and phosphate levels in the blood.

Understanding the normal levels of these hormones is crucial for diagnosing and managing thyroid disorders.

Decoding TSH: The Key to Thyroid Function Assessment

Thyroid Stimulating Hormone (TSH) is the primary indicator used by healthcare professionals to evaluate thyroid function. Produced by the pituitary gland in the brain, TSH plays a vital role in regulating the production and release of thyroid hormones.

How does TSH work? When thyroid hormone levels in the blood are low, the pituitary gland releases more TSH to stimulate the thyroid gland to produce more hormones. Conversely, when thyroid hormone levels are high, TSH production decreases.

Normal TSH Levels

What are considered normal TSH levels? For adults with no symptoms of thyroid dysfunction, the normal range is typically between 0.4 and 4.0 mIU/L (milliunits per liter). However, it’s important to note that some experts suggest a narrower range of 0.5 to 2.5 mIU/L as optimal.

Should you be concerned if your TSH is above 2.0 mIU/L? While values between 2.0 and 4.0 mIU/L are still considered within the normal range, some studies suggest that individuals with TSH levels in this range may have an increased risk of developing hypothyroidism in the future. If your TSH falls in this range, it’s advisable to have regular check-ups with your healthcare provider.

Understanding T4 and T3: The Active Players in Thyroid Function

While TSH is crucial for assessing thyroid function, understanding T4 and T3 levels is equally important for a comprehensive evaluation of thyroid health.

T4 (Thyroxine)

T4 is the primary hormone produced by the thyroid gland. It exists in two forms:

• Free T4: The active, unbound form that is available for use by the body’s cells.
• Total T4: The total amount of T4 in the blood, including both free and protein-bound forms.

What are normal T4 levels? The typical range for free T4 is 0.8 to 1.8 ng/dL (nanograms per deciliter), while total T4 ranges from 4.5 to 11.2 μg/dL (micrograms per deciliter).

T3 (Triiodothyronine)

T3 is the active form of thyroid hormone that affects various bodily functions. Like T4, it exists in free and total forms:

• Free T3: The unbound, active form of T3.
• Total T3: The total amount of T3 in the blood, including both free and protein-bound forms.

What are normal T3 levels? The typical range for free T3 is 2.3 to 4.2 pg/mL (picograms per milliliter), while total T3 ranges from 80 to 200 ng/dL.

Factors Influencing Thyroid Hormone Levels

Several factors can affect thyroid hormone levels, leading to fluctuations in TSH, T4, and T3. Understanding these factors is crucial for accurate interpretation of thyroid function tests:

1. Age: Thyroid function can change with age, with TSH levels tending to increase in older adults.
2. Pregnancy: Hormonal changes during pregnancy can affect thyroid function and hormone levels.
3. Medications: Certain medications, such as amiodarone, lithium, and some antidepressants, can influence thyroid hormone levels.
4. Iodine intake: Both excessive and insufficient iodine intake can affect thyroid function.
5. Stress: Chronic stress can impact thyroid hormone production and metabolism.
6. Autoimmune disorders: Conditions like Hashimoto’s thyroiditis can affect thyroid function and hormone levels.
7. Time of day: TSH levels can fluctuate throughout the day, with highest levels typically occurring in the early morning.

Is it necessary to fast before a thyroid function test? In most cases, fasting is not required for thyroid function tests. However, it’s always best to follow your healthcare provider’s specific instructions.

Recognizing Signs of Thyroid Dysfunction

Thyroid dysfunction can manifest as either an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism). Recognizing the signs and symptoms of these conditions is crucial for early detection and treatment.

Hyperthyroidism Symptoms

• Unexplained weight loss
• Rapid heartbeat or palpitations
• Increased appetite
• Nervousness and anxiety
• Tremors in hands and fingers
• Excessive sweating
• Changes in menstrual patterns
• Increased sensitivity to heat

Hypothyroidism Symptoms

• Unexplained weight gain
• Fatigue and weakness
• Increased sensitivity to cold
• Dry skin and hair
• Constipation
• Depression
• Muscle aches and joint pain
• Irregular or heavy menstrual periods

When should you consult a healthcare provider about thyroid function? If you experience persistent symptoms associated with thyroid dysfunction or have risk factors such as a family history of thyroid disorders, it’s advisable to seek medical evaluation.

Diagnosing Thyroid Disorders: Beyond TSH

While TSH is the primary screening test for thyroid function, additional tests may be necessary for a comprehensive evaluation of thyroid health. These tests can help diagnose specific thyroid disorders and guide treatment decisions.

Additional Thyroid Function Tests

• Free T4 and Free T3: These tests measure the active forms of thyroid hormones in the blood.
• Thyroid Antibody Tests: These tests check for antibodies that may indicate autoimmune thyroid disorders such as Hashimoto’s thyroiditis or Graves’ disease.
• Thyroid Ultrasound: This imaging test can detect structural abnormalities in the thyroid gland, such as nodules or enlargement.
• Radioactive Iodine Uptake Test: This test helps evaluate thyroid function and can be useful in diagnosing hyperthyroidism.

How often should thyroid function be tested? For individuals with no known thyroid issues, screening every 5 years is typically recommended, starting at age 35. However, those with risk factors or existing thyroid conditions may require more frequent testing.

Treatment Options for Thyroid Disorders

The treatment of thyroid disorders depends on the specific condition and its severity. Here are some common treatment approaches:

Hypothyroidism Treatment

The standard treatment for hypothyroidism is thyroid hormone replacement therapy, typically with levothyroxine (synthetic T4). This medication helps restore normal thyroid hormone levels and alleviate symptoms.

How long does it take for thyroid medication to work? While some individuals may notice improvements within a few weeks, it can take several months to achieve optimal thyroid hormone levels and symptom relief.

Hyperthyroidism Treatment

Treatment options for hyperthyroidism include:

• Antithyroid medications: These drugs help reduce thyroid hormone production.
• Radioactive iodine therapy: This treatment destroys overactive thyroid cells.
• Thyroidectomy: Surgical removal of part or all of the thyroid gland may be necessary in some cases.

Is it possible to treat thyroid disorders naturally? While some lifestyle changes and dietary modifications may support thyroid health, it’s crucial to work with a healthcare provider for proper diagnosis and treatment of thyroid disorders.

Living with Thyroid Disorders: Lifestyle Considerations

Managing a thyroid disorder often involves more than just medication. Lifestyle factors can play a significant role in supporting thyroid health and overall well-being.

Dietary Considerations

A balanced diet is essential for thyroid health. Key nutrients to focus on include:

• Iodine: Essential for thyroid hormone production
• Selenium: Supports thyroid hormone metabolism
• Zinc: Aids in thyroid hormone synthesis
• Vitamin D: Important for immune function and thyroid health

Are there foods to avoid with thyroid disorders? Some foods, such as soy products and cruciferous vegetables, may interfere with thyroid function when consumed in large amounts. However, moderate consumption is generally safe for most individuals.

Exercise and Thyroid Health

Regular physical activity can support thyroid function and help manage symptoms associated with thyroid disorders. However, it’s important to adjust exercise intensity based on your energy levels and thyroid status.

Stress Management

Chronic stress can impact thyroid function. Incorporating stress-reduction techniques such as meditation, yoga, or deep breathing exercises can be beneficial for overall thyroid health.

How can you support your thyroid health naturally? While medical treatment is essential for thyroid disorders, adopting a healthy lifestyle, managing stress, and ensuring adequate nutrition can complement conventional treatments and support overall thyroid function.

The Future of Thyroid Care: Emerging Research and Treatments

The field of thyroid research is continually evolving, with new insights and potential treatments on the horizon. Some areas of ongoing research include:

• Personalized medicine approaches for thyroid disorders
• Novel drug therapies for treatment-resistant thyroid conditions
• Improved diagnostic tools for early detection of thyroid dysfunction
• Exploration of the gut-thyroid axis and its role in thyroid health

What advancements can we expect in thyroid care? While it’s difficult to predict specific breakthroughs, ongoing research promises to enhance our understanding of thyroid function and improve treatment options for individuals with thyroid disorders.

In conclusion, understanding normal thyroid hormone levels and the factors that influence them is crucial for maintaining optimal thyroid health. Regular check-ups, awareness of symptoms, and working closely with healthcare providers can help ensure timely diagnosis and effective management of thyroid disorders. As research in this field continues to advance, we can look forward to improved diagnostic tools and treatment options for thyroid conditions in the future.

TSH Test – Endocrine Surgery

Definition:
TSH is a test that measures the amount of the hormone TSH in the blood.

Alternative Names: Thyrotropin; Thyroid stimulating hormone

How the test is performed:

Adult or child:

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to fill with blood. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. The tourniquet is then removed to restore circulation. After blood has been collected the needle is removed, and the puncture site is covered to stop any bleeding.

Infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. A bandage may be applied to the puncture site if there is any bleeding.

How to prepare for the test:
No special preparation is usually necessary.

How the test will feel:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed:
TSH is measured as a screening test for abnormal thyroid function (either hyperthyrodism or hypothyrodism). It is also measured to monitor treatment of these conditions. The test is also done in infertile females, to check if thyroid disease is the cause of infertility.

TRH, a hormone produced in the hypothalamus, stimulates the pituitary gland to release TSH. TSH subsequently stimulates the thyroid to produce thyroid hormones, T3 and T4. These hormones feedback to the hypothalamus and pituitary to regulate the release of both TSH and TRH.

In certain diseases, this regulation pathway is altered, leading to under- or over-production of thyroid hormone. When a thyroid disorder is suspected clinically, a TSH level is obtained as an initial test.

Normal Values:
Normal values are from 0.4 to 4.0 mIU/L for those with no symptoms of an under- or over-active thyroid.

Some people with a TSH value over 2.0 mIU/L, who have no signs or symptoms suggestive of an under-active thyroid, may develop hypothyroidism sometime in the future. Anyone with a TSH above 2.0 mIU/L, therefore, should be followed very closely by a doctor.

Normal value ranges may vary slightly among different laboratories.

What abnormal results mean:

Greater-than-normal levels may indicate:

• Congenital hypothyroidism (cretinism)
• Primary hypothyroidism
• TSH-dependent hyperthyroidism
• Thyroid hormone resistance
• Exposure to mice (lab workers or veternarians)

Lower-than-normal levels may indicate:

• Hyperthyroidism
• TSH deficiency
• Medications (dopamine agnoists, glucocorticoids, somatostatin analogues, bexarotine)

What the risks are:

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)
• Multiple punctures to locate veins

Special considerations:
Drugs that can affect TSH measurements include: antithyroid medications, lithium, potassium iodide, amiodarone, dopamine and prednisone. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

What Are Considered Normal Thyroid Hormone Levels?

Your thyroid gland is an essential part of your endocrine system that secretes hormones that regulate metabolism, heart function, digestion, muscles, brain development, and bone health.

In this article, we’ll talk about typical thyroid hormone levels, which tests are important, and what to do if you have hypothyroidism.

What are thyroid hormones?

Thyroid hormones are secreted by the thyroid gland — the butterfly-shaped organ at the base of your neck. Three thyroid hormones exist, but T4 and T3 are the most prominent.

Here’s what each thyroid hormone does within the body:

• T4 (thyroxine) is the primary hormone produced by the thyroid gland. Also known as tetraiodothyronine, T4 is inactive. Its primary function is to become active T3.
• T3 (triiodothyronine) is the active form of T4. It regulates your metabolism and other vital functions. Just 20% is produced in the thyroid, while most T3 is made in other organs (like the kidneys and liver) from T4.
• Calcitonin is the less prominent hormone that your thyroid gland produces. It helps regulate calcium and phosphate levels in your blood, contributing to healthy bones.

TSH And Its Role In Thyroid Function

TSH stands for Thyroid Stimulating Hormone. It’s the primary hormone checked by doctors to assess thyroid function. TSH is secreted in the brain by the pituitary gland, not the thyroid gland. 

The pituitary gland will secrete more TSH in response to sensing a need for more thyroid hormone production. TSH then travels to the thyroid gland (in the neck) and, as its name implies, stimulates it to make more thyroid hormone. TSH is one of your body’s natural defenses against hormone imbalance.

Symptoms Of A Thyroid Issue – Understanding Thyroid Levels

What are the symptoms of a thyroid problem? The symptoms of a thyroid problem comes from hyperthyroidism or hypothyroidism, both caused by unbalanced thyroid levels.

Thyroid disease symptoms include:

• Enlarged thyroid (goiter)
• Exhaustion
• Weight gain or weight loss
• Muscle and joint pain
• Dry skin
• Thinning hair or nails
• Temperature intolerance
• Digestive problems
• Depression and other mood disorders
• Irregular heartbeat
• Swelling
• Eye problems

Graves’ disease (which may lead to hyperthyroidism) or Hashimoto’s thyroiditis (which may lead to hypothyroidism) can lead to dangerously high or dangerously low thyroid hormone levels, respectively. There are many triggers for Graves’ or Hashimoto’s.

It’s crucial to know if a patient’s thyroid imbalance is due to Hashimoto’s or Grave’s disease — these are autoimmune conditions with a significantly different root cause and treatment strategy than thyroid disease — which is not autoimmune.

Optimal TSH Levels

Optimal TSH hormone levels are 0.5-5.0 mIU/L, according to the mainstream medical community. We recommend 0.5-2.5 mIU/L, though — especially for pregnant women.

Pregnancy tends to reduce TSH hormone levels. You may dip below 0.5 mIU/L but remain euthyroid (which means your thyroid is healthy). Thyroid hormone levels may rise with each trimester, then spike postpartum, but this is perfectly normal in the short term.

Thyroid hormone levels are measured with blood tests.

What is a normal TSH level in a woman? An optimal TSH level in a woman is 0. 4-2.5 mIU/L. For pregnant women, that upper limit is stricter than if you are not pregnant.

A dangerously high level of TSH is above 5.0 mIU/L. High TSH means low thyroid hormones. This could indicate severe hypothyroidism.

What is considered a low thyroid level? A TSH level of 4.5 mIU/L and above typically indicates hypothyroidism.

Testing For T3, T4, And TSH Thyroid Levels

Many conventional primary care doctors and endocrinologists focus primarily on TSH levels. Here at PrimeHealth, we administer a more robust set of thyroid function tests than most of the medical community.

Additionally, it’s important to consider optimal levels versus reference range levels. That’s why we administer a more thorough panel of tests to hypothyroid patients. 

It’s important to remember that if you’re taking thyroid medications, the time from your last dose will change how we interpret your lab values. Your provider may have you test your thyroid panel before or after taking your medication in the morning to assess your thyroid levels at various times during the day.

We believe the most accurate and thorough way to test for thyroid function is to measure:

• TSH levels
• Free T4
• Free T3
• Total T4
• Total T3
• Reverse T3
• Anti-thyroglobulin and anti-TPO antibodies (Hashimoto’s thyroid antibodies)
• Thyroid-binding globulin (TBG levels)

Important: Make sure you’re not taking biotin (vitamin B7) when testing for thyroid hormone levels. This popular supplement for hair and nail growth can interfere with test results.

What are normal TSH test results for Thyroid levels? The normal range of thyroid test results is 0.5-5.0 mIU/L, but we recommend TSH levels stay under 2.5 mIU/L. If your TSH level sits outside this reference range, you probably suffer from a thyroid disorder that needs to be treated.

T4 Test

Testing free T4 levels is standard practice for some medical practitioners. We also test total T4 for a complete picture. Both of these are blood tests. 

Our goal during treatment is to optimize our patients’ thyroid hormone levels to be in the middle-to-upper end of these thyroid hormone ranges (for free and total T4 and T3).

Typical T4 levels should be:

• Total T4 = 0.4-2.5 mIU/L or 5,000-12,000 ng/dL (nanograms per deciliter of blood)
• Free T4 = 0.9-1.9 ng/dL

T3 Test

A lot of healthcare professionals don’t test for T3 levels. We believe testing T3 levels is crucial to understanding a fuller picture of your thyroid function.

We test the following T3 levels: total T3, free T3, and reverse T3. These all can be measured via a blood test.

Typical T3 levels should be:

• Total T3 = 75-195 ng/dL (nanograms per deciliter of blood)
• Free T3 = 2.3 – 4.2  pg/dL
• Reverse T3 = 10-24 ng/dL
  • Optimal reverse T3 levels would be around 15. Higher values are indicative of inflammation or stress (mental or physical).

TSH Test

Testing levels of TSH is a common and critical part of any health practitioner diagnosing thyroid disorders. A blood test is the typical way to assess TSH levels.

The American Thyroid Association recommends serum TSH levels stay 0.4-4.0 mIU/L (milli-international units per liter). We recommend keeping that number even lower — below 2.5 mIU/L.

However, we recommend keeping TSH levels between 0.5 and  2.5 mIU/L. If your TSH levels are too high, you may be hypothyroid. If your thyroid levels are too low, you may be hyperthyroid.

High Vs. Low TSH

Elevated TSH levels mean that you have primary hypothyroidism or subclinical hypothyroidism. The problem in primary hypothyroidism is that your thyroid gland is not producing enough thyroid hormone, so the pituitary gland is doing its job by trying to stimulate the thyroid with increased TSH levels.  

In subclinical hypothyroidism, the TSH is elevated, while the thyroid hormone levels are still in the normal reference range.  

Low TSH levels either means that the pituitary gland is not functioning and you could have secondary hypothyroidism, or that you have hyperthyroidism (most likely from Grave’s disease).

Neither high nor low TSH is less of a problem than the other. Both need to be addressed.

What does a high TSH mean?

What can happen if the TSH level is too high? If a TSH level is too high, it may be a sign of hypothyroidism. Here are some of the symptoms of hypothyroidism:

• Enlarged thyroid (goiter)
• Fatigue
• Weight gain
• Muscle and joint pain
• Hoarse voice, snoring
• Dry skin
• Thinning hair
• Brittle nails
• Cold intolerance
• Constipation
• Depression
• Heart disease
• Myxedema coma

There are two main forms of hypothyroidism or an underactive thyroid:

1. Primary hypothyroidism is when your thyroid is the problem. There’s not another part of your body triggering thyroid dysfunction.
2. Thyroid-stimulating hormone (TSH) is not a thyroid hormone. TSH is produced in the pituitary gland, but it dramatically affects the thyroid. If you produce too little TSH, you could suffer from secondary hypothyroidism, which means your thyroid disorder is a pituitary problem.

Another form of secondary hypothyroidism, or tertiary hypothyroidism, occurs when your hypothalamus releases too little thyrotropin. This issue with the hypothalamus can affect the pituitary gland, which in turn affects the thyroid gland.

What may be causing high TSH? Autoimmune diseases such as Hashimoto’s, toxin exposure, or even food allergies may be causing high TSH levels, which is due to low thyroid hormone levels and hypothyroidism.

What does a low TSH mean?

A low TSH level means you either suffer from secondary hypothyroidism or hyperthyroidism. This means your thyroid gland is making too much thyroid hormone.

The symptoms of hyperthyroidism include:

• Muscle weakness
• Too much energy
• Insomnia
• Fatigue
• Heat sensitivity
• Diarrhea
• Frequent urination
• Thirst
• Itchiness
• Anxiety
• Mood swings
• Osteoporosis

What may be causing low TSH? Common causes of low TSH levels include:

• Autoimmune diseases
• Thyroid nodules
• Inflammation
• Inactive or underactive pituitary or hypothalamus glands
• Medication side effects

When is treatment needed?

Treatment is needed when your thyroid levels are too high or too low, ranging outside the optimal levels. Normal TSH levels are typically considered 0.5-5.0 mIU/L. We prefer the upper limit to be 2. 5 mIU/L.

Thyroid hormone replacement using levothyroxine is the most common treatment for an underactive thyroid (too little thyroid hormone). Usually, thyroid medications like levothyroxine are not our first response to treating thyroid dysfunction.

Radioactive iodine, antithyroid agents, and beta-blockers are the most common treatments for an overactive thyroid.

There are many different root causes of thyroid conditions. The best treatment for either hypothyroidism or hyperthyroidism is addressing your unique root cause, such as stress, leaky gut syndrome, toxin exposure, nutrient deficiencies, inflammatory diet, or thyroid cancer.

Here at PrimeHealth, we do just that — create individual, integrative treatments that impact the root cause of your thyroid levels.

Thyroid questions? Let us answer them.

Now you know all about normal thyroid hormone levels and when to seek help from a healthcare provider.

PrimeHealth is devoted to answering people’s questions about medical conditions and autoimmune diseases like Hashimoto’s thyroiditis. We believe it’s important to make patients feel heard and educate them on what is going on in their bodies.

Did you know — a lot of people’s hypothyroidism can be permanently cured. Even what conventional endocrinology specialists might call “permanent hypothyroidism” may be treatable. Our patients prove it.

To schedule a FREE phone consultation with a medical staff member, schedule your appointment today.

Sources

1. Armstrong, M., Asuka, E., & Fingeret, A. (2020). Physiology, thyroid function. StatPearls [Internet].
2. Dunlap, D. B. (1990). Thyroid function tests. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. 
3. Delitala, A. P., Scuteri, A., & Doria, C. (2020). Thyroid hormone diseases and osteoporosis. Journal of clinical medicine, 9(4), 1034.
4. Udovcic, M., Pena, R. H., Patham, B., Tabatabai, L., & Kansara, A. (2017). Hypothyroidism and the heart. Methodist DeBakey cardiovascular journal, 13(2), 55.

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tests, symptoms of thyroid problems in men and women

In recent months, I quickly get tired, my head often hurts, and it has also become difficult for me to concentrate on work. This was not the case before. I have no problems with my colleagues or my family, I try to maintain a balance of work and leisure, so I don’t think it’s a matter of psychology.

I don’t want to go to the doctor yet, because I don’t have any serious complaints, and I just don’t understand what to talk about with him. But somewhere I heard that the problem could be in the thyroid gland. Is it possible to take tests on my own to check the functioning of the thyroid gland, and which ones? If it turns out that something is wrong, I will already have something to show to a specialist.

Daniil Davydov

medical journalist

Author profile

To check the health of the thyroid gland, just one test is enough – for thyroid stimulating hormone, or TSH. You can donate blood for TSH at any commercial laboratory.

But it’s not a fact that your symptoms are related to thyroid disease. Similar problems occur in people with cardiovascular disease, type 2 diabetes, anemia, and many other diseases.

Before paying for an analysis, which may not be necessary in your case, it is better to see a doctor. The doctor will ask you about your well-being, assess your condition and give you a referral for research that will definitely be useful in your case.

What is the thyroid gland and why is it needed? It is shaped like a butterfly.

How the thyroid gland works – Medscape 9 International Medical Directory0003

The gland is located on the front surface of the neck, just below the thyroid cartilage – in men, this part of the body forms the Adam’s apple. The wings of the thyroid gland lie on top of the trachea, or windpipe, through this cartilaginous tube air passes into the lungs.

The thyroid gland lies almost under the surface of the skin. They are separated only by fasciae – thin plates of connective tissue

The task of the thyroid gland is to absorb iodine and, on its basis, create thyroid hormone. This substance exists in the body in two forms. Approximately 90% is accounted for by a less active form of the hormone – thyroxine, or T4. The rest goes to the more active form called triiodothyronine, or T3.

Thyroid hormones enter the bloodstream and are carried throughout the body. They bind to almost all cells that make up the human body and encourage them to increase the metabolic rate: break down glucose more intensively and synthesize proteins. This gives the body a lot of opportunities for self-regulation.

Why Thyroid Hormones Are Necessary – A Primer for Medical Students Statpearls

Thanks to T3 and T4 body:

1. Manages the exchange of energy. By increasing the level of hormones in the blood, the body can, for example, speed up wound healing.
2. Regulates body temperature. By increasing the level of hormones in the blood, the body speeds up the metabolism and heats up.
3. Governs the growth of the organism in childhood.
4. Regulates sperm production in men and menstruation in women.
5. Activates the nervous system, that is, makes a person cheerful, attentive and alert.

But if the thyroid hormone levels are high for too long, the body will use up energy reserves very quickly. And if it is low, the body will not be able to use energy reserves: storage cells give out reserves only according to the invoice, the role of which is played by thyroid hormones. To prevent this from happening, the brain vigilantly controls the level of T3 and T4 in the blood.

How the Brain Controls Blood T3 and T4 Levels – An International Physician’s Guide Uptodate

Once the brain receives the signal that the body is lacking T3 and T4, it causes a gland in the brain, the pituitary gland, to release thyroid-stimulating hormone, or TSH, into the blood . The thyroid-stimulating hormone tells the thyroid gland to increase the synthesis of T3 and T4. As soon as the level of thyroid hormones in the blood reaches a normal value, the pituitary gland receives a signal that it is time to stop secreting TSH. As a result, the normal level of T3 and T4 is maintained all the time.

Activation of the thyroid gland is indicated by a blue arrow, and deactivation of the pituitary gland is shown by a red arrow. The pituitary gland and the thyroid gland regulate each other’s work – this is called a feedback loop

How do people who have problems with the thyroid gland feel

While the thyroid gland is healthy, it has enough building materials and it receives valuable instructions from the brain in a timely manner, level T3 and T4 in the blood within the normal range – and the person feels good. But if the regulation system breaks down, health problems arise. They can be divided into two large groups:

1. Hyperthyroidism, when the thyroid gland produces too many hormones.
2. Hypothyroidism, when the thyroid gland produces too little hormone.

The problem is that thyroid hormones affect almost the entire body. Therefore, it is difficult to figure out what exactly has broken down in the body, focusing only on the symptoms of these diseases.

For example, in hyperthyroidism people become nervous and irritable, get tired quickly, suffer from muscle weakness and insomnia. Some quickly and effortlessly lose weight, while others begin to tremble slightly. Many diseases begin with similar symptoms – from viral and bacterial infections to depression.

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Thyroid Problems: How to Identify and Correct

People suffering from hypothyroidism often experience swelling, weight gain, decreased performance, voice becomes hoarse, skin dry and flaky, and hair sparse and coarse. These symptoms are also found in a wide variety of diseases, from type 2 diabetes to skin diseases.

The only unique symptom seen in severe thyroid problems is goiter. This is the name of the situation when the thyroid gland is so enlarged in size that the neck swells. At the same time, a goiter can form both with hypothyroidism and hyperthyroidism, so even with serious problems with the thyroid gland, it is still impossible to figure out what exactly is the matter without an examination by an endocrinologist.

How to evaluate the functioning of the thyroid gland

There is still a way to distinguish thyroid problems from other diseases.

This is a blood serum test for thyroid-stimulating hormone levels. The fact is that the level of thyroid hormones is immediately reflected in the level of TSH. And if the concentration of this hormone is higher or lower than normal, we can say with a high degree of certainty that something is wrong with the thyroid gland.

What tests are best for primary thyroid testing – Uptodate

The normal level of TSH in the blood of an adult non-pregnant person is 0.3-4.5 mIU / l. If TSH in the blood is less than normal, the thyroid gland is working too actively, that is, there are a lot of T3 and T4 in the blood. This may indicate hyperthyroidism. And if there is too much TSH, the thyroid gland is not active enough, that is, there are few thyroid hormones in the blood. Then hypothyroidism can be suspected.

Transcription of Clinical Lab Tests – C. Higgins Reference PDF, 17.7 MB

However, it is impossible to make an accurate diagnosis based on TSH results alone. If the analysis shows that you have a problem with the thyroid gland, it makes sense to contact an endocrinologist – he will tell you what additional studies to undergo.

As a rule, at this stage, the doctor prescribes tests for the level of free T4, and sometimes free T3. The normal level of free T4 in the blood is 9-26 pmol/l, and T3 is 3.0-9.0 pmol/l.

TSH analysis – Medlineplus

What problems can the ratio of TSH and free T4 indicate

TSH slightly elevated

T4 normal

Possibly mild hypothyroidism

T4 high

–

T4 low

–

TSH high

T4 normal

–

T4 high

– 9000 3

T4 low

Hypothyroidism

TSH low

T4 normal

Possibly this is hyperthyroidism

T4 high

Hyperthyroidism

T4 low

Hypothyroidism associated with pituitary insufficiency

T3. This hormone is 3-4 times more active than T4, and at the same time it is much less. Therefore, if the level of T3 is above normal, we are talking about hyperthyroidism. And if T3 is normal, symptoms resembling hyperthyroidism are most likely associated with other causes.

Prices for analyzes in KDL and Helix laboratories together with taking biomaterial in Moscow

TSH test

715 R

Free T4 test

745 R

Free T3 test

9000 2,750 R

Total

2210 R

Helix

TSH test

715 R

Free T4 test

740 R

Free T3 test

740 R

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2195 R

What causes thyroid disease

After the doctor diagnoses hyperthyroidism or hypothyroidism, he will need to find out exactly what led to this disease. This is a very difficult task.

Autoimmune diseases. This is the name of diseases in which cells of the immune system create fighting proteins-antibodies not against microbes, but against cells of their own thyroid gland.

The immune system is capable of producing two types of these antibodies: stimulating and blocking. Stimulating antibodies work like a fake TSH, that is, they induce the thyroid gland to produce too much T3 and T4. In Graves’ disease, stimulatory antibodies are mainly produced, due to which hyperthyroidism develops.

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But there are autoimmune diseases, such as Hashimoto’s thyroiditis, in which blocking antibodies are produced that prevent the thyroid gland from receiving orders from TSH and creating hormones. Because of this, hormone deficiency, or hypothyroidism, develops.

Thyroiditis is an inflammation of the thyroid gland that usually leads to hyperthyroidism. It is often caused by autoimmune diseases, but this is not the only reason. Thyroiditis can develop as a complication of radiation therapy, a severe bacterial or viral infection such as the flu or measles, or certain medications.

Too much or too little iodine. If too much iodine is taken in through food or supplements, the thyroid gland can either become underactive or produce too much T3 and T4. That is, excess iodine can cause both hypothyroidism and hyperthyroidism.

But if there is not enough iodine, then the thyroid gland simply has nothing to make hormones from – in this situation, hypothyroidism always develops.

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Thyroid problems can also be triggered by pregnancy, failed thyroid surgery, and congenital pituitary deficiency that prevents it from producing enough TSH.

There are tests to find out the exact cause of thyroid disease, but it is difficult to understand them. For example, to distinguish an autoimmune disease from iodine deficiency and other problems, tests for levels of antibodies to various thyroid proteins are commonly used.

But since there are many autoimmune diseases, it is pointless to take all tests from this category at random. The doctor must choose the right test – without him, it will not be possible to understand what is the cause of the disease, and it will still not be possible to choose the right treatment.

What is the result

Thyroid hormones affect all body systems. Therefore, if something goes wrong, there are symptoms that can indicate a variety of health problems.

To distinguish thyroid disease from other health problems, you can take a blood test for TSH levels. If the result differs from the norm, it makes sense to consult an endocrinologist.

An analysis of the TSH level only says that not everything is in order with the thyroid gland. To make an accurate diagnosis, on which the treatment will depend, clarifying tests are needed. But since there are a lot of reasons that can lead to thyroid diseases, a doctor should select clarifying tests and decipher them.

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Checking the thyroid gland in MedExpert Yaroslavl

The thyroid gland is a very small organ located in our throat area, under the larynx. Normally, it weighs no more than 20 grams, consists of two lobes and an isthmus. The thyroid gland synthesizes thyroid hormones; T3 – triiodothyronine, T4 – thyroxine and calciotonin (parathyroid hormone) – regulating calcium levels.

The first two hormones are responsible for the physical, mental state of the body, seriously affect the immune system, stimulating the production of T-cells. With the most active participation of these hormones, almost all metabolic processes in the body are performed, a constant body temperature is maintained, and energy is produced. Will an orchestra play without a conductor?

It will probably be, but we won’t hear a beautiful, well-coordinated melody. So it is with the thyroid gland, it regulates all the endocrine glands, affects the metabolism, determines our well-being on a global scale, so to speak. Accordingly, if the conductor (our thyroid gland) is ill, can hardly stand on his feet and impulsively pulls his arms, the symphony will not work. Here it will not be up to the game, if only to somehow survive. And the body, exhausted and unbalanced, endures … until the first serious illness, until the first weakness …

It’s not just sex hormones that affect how you look and feel. Among the most influential are also the hormones produced by the thyroid gland.

Thyroid too low and you feel like an amoeba. Yes, hypothyroidism makes you feel like you just want to lie on the couch with a bag of chips all day. Everything works slower, including your heart, intestines, and your brain. A general drop in brain activity in hypothyroidism leads to depression, cognitive impairment, anxiety, and mental fog.

The thyroid gland controls the production of many neurotransmitters. Among them are serotonin, dopamine, adrenaline and norepinephrine. An underactive thyroid can lead to a compensatory increase in adrenaline (produced by the adrenal glands), which makes you feel constantly tense, as well as cortisol, another stress hormone. Thus, you feel tired, tense and stressed at the same time.

Experts conservatively estimate that one third of all depression is directly related to thyroid imbalance. More than 80% of people with mild hypothyroidism have poor memory.

Symptoms of underactive thyroid:

• Feeling chilly;
• Weight gain;
• Constipation;
• Fatigue;
• High cholesterol;
• High blood pressure;
• Dry, thinning hair or lack of hair, especially on the eyebrows, where one third of the hairline is often missing;
• Dry skin;
• Dry eye syndrome;
• Thin, broken or flaking nails;
• Irregular menses;
• Endometriosis;
• Infertility;
• Miscarriage;
• Severe menopause.

Even if your thyroid is slightly underactive, you may still have symptoms of what is known as subclinical hypothyroidism. If you are chronically fatigued, overweight, dry skin, dizzy, depressed, constantly cold, and if your body temperature is consistently below 36.6 degrees, then you may have an underactive thyroid gland.

An overactive thyroid causes hyperthyroidism. In this state, everything in the body is working too fast, including the heart, intestines, and digestion, as if you are rushing forward at crazy speed. A person feels nervous and nervous, as after large doses of caffeine. If you suffer from insomnia, anxiety, irritability, chaotic thinking, rapid heart rate, shortness of breath, weight loss despite increased appetite, unreasonable fever, then you may have an overactive thyroid gland. In extreme cases, other characteristic signs appear: goiter (an outgrowth on the thyroid gland), significant weight loss, bulging eyes.

What does the thyroid gland suffer from?

The thyroid gland is a small, butterfly-shaped gland located in the lower part of the neck. When the doctor runs his hands along the base of the throat, he checks for an obvious enlargement of your thyroid gland. But without a blood test, it is impossible to say exactly what is happening there. And it may take some time to optimize the thyroid gland.

The main thyroid-related hormones – TSH, T3, T4 – must be balanced. Tens of millions of people around the world (5-25% of the world’s population) are thought to have thyroid problems. In their book Thyroid Mental Power, Richard and Carily Shames write that “Over the past 40 years, we have witnessed a significant increase in the number of synthetic chemicals that lead to hormonal disorders. These substances penetrate our air, food and water… the most sensitive human tissue turned out to be the thyroid gland.”

Most thyroid problems are autoimmune, where the body attacks itself. This may be due to environmental toxins present in the body or an allergy to the food we eat or something in the air we breathe. It is suspected that the recent dramatic increase in hypothyroidism may be due to the fact that the toxins we ingest interfere with the peripheral conversion of T4 to T3.

Thyroid depressant factors:

• Too much stress and cortisol;
• Selenium deficiency;
• Protein deficiency, excess sugar;
• Chronic diseases;
• Liver or kidney disorders;
• Cadmium, mercury, lead poisoning;
• Herbicides, pesticides;
• Birth control pills, excessive estrogen production.

Problems with the thyroid gland – after the birth of a child.

Thyroid problems can occur at any time in a woman’s life. But a particularly vulnerable period is the birth of a child. During pregnancy, the immune system relaxes somewhat so that immune cells and antibodies do not reject the placenta, with which the baby feeds. This is why many women with thyroid problems believe that pregnancy is the best state of their lives.

However, nine months later, the situation changes. The baby is born, the placenta is gone, and the immune system functions that were shut down to prevent early placental rejection are now turning on dramatically. It is well known that thyroid disorders usually return within 6 months after childbirth. According to researchers from Charles University in Prague, in 35% of women who have antibodies to their own thyroid gland, 2 years after the birth of a child, the thyroid gland begins to malfunction again.

Having a thyroid problem when you’re struggling to cope with a 2 year old is a disaster. Studies indicate that about 70% of women who suffer from hypothyroidism in the postpartum period become careless and make more mistakes when caring for their children.

Thyroid problems are one of the main causes of postpartum depression and anxiety. According to one study, 80-90% of cases of postpartum depression are associated with thyroid disorders. And without effective treatment, it is impossible to recover.

The post-pregnancy period is not the only vulnerable period in this regard. It has been estimated that one in four postmenopausal women has a thyroid imbalance.

How to check the thyroid gland?

You can check your thyroid gland with a blood test. Do not settle for TSH (pituitary thyroid stimulating hormone) analysis alone. Its levels may be normal even when you have undiagnosed thyroid problems.

Insist that the doctor check the following:

• TSH (According to the American Association of Clinical Endocrinologists, values ​​above 3.0 are abnormal and need further testing)
• Free T3 (active)
• Free T4 (inactive)

Thyroid antibodies: thyroid peroxidase antibodies (TPO Ab) and thyroglobulin antibodies (TG Ab).

Liver function test. The fact is that 95% of T4 is activated in the liver, so the condition of the liver should be taken into account.

Ferritin level. Ferritin transports active T3 into cells. It should be over 90.

These tests may be helpful, but you still need to be diagnosed by a doctor. If you have thyroid problems, they can be effectively treated with a range of medications. Your doctor should check your thyroid hormone levels regularly to make sure you are not taking too much or too little of your medication.