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Alt liver enzyme range: High, Low & Normal Results, Symptoms & Causes

What Does It Mean When Your ALT Is High? > Personalabs

Getting elevated alanine aminotransferase (ALT) or serum glutamic-pyruvic transaminase (SGPT) in your liver function test can be distressing. But what high ALT means depends on factors such as the medications you’re taking, underlying liver disorders, chronic drinking, and consumption of herbal medicine. 

Understanding the roles of ALT and its sudden spike in the bloodstream will provide clues on your liver health. Read more about it in the next few lines. 

What Is an ALT Lab Test? 

An ALT blood test measures the alanine aminotransferase (ALT) enzyme level to detect liver damage caused by diseases like hepatitis or lifestyle factors such as habitual drinking. The enzyme is an ideal marker for health conditions concerning the liver as it is released to the bloodstream when the liver sustains injuries or undergoes dysfunction. 

However, ALT bloodwork does not produce conclusive results on its own. Therefore, it is usually taken as part of the hepatic function panel test and comprehensive metabolic panel, along with other blood tests for other liver enzymes.  

In some cases, you might take the ALT blood test first, followed by other labwork to confirm a suspected condition or the other way around. These tests include:

  • AST (aspartate aminotransferase) test
  • GGT (gamma-glutamyl transferase) test
  • ALP (alkaline phosphatase) test
  • ALB (albumin) test
  • Total bilirubin blood test

ALT Blood Test: Preparation and Results Meaning 

Measuring ALT levels is done through blood work, wherein you will have to visit a laboratory for a phlebotomist to collect your blood sample. 

Although there is no special preparation before the blood collection for an ALT blood test, you may need to fast if you take it alongside other tests. For example, if it is part of a liver function panel where a bilirubin lab test is involved, you will need to abstain from food and drinks for about 8 hours before the test. 

What Does It Mean When Your ALT Is High?

Your ALT level is considered high if it exceeds the normal range of 0 to 44 IU/L. Some laboratories may present a slightly different reference interval, but a test result of 55 IU/L or above could indicate liver problems. If the value exceeds the upper limit of the normal range, it could suggest liver disease or cirrhosis (tissue scarring).  

However, other factors could contribute to the increase of ALT in your blood – not just liver disorders. Here are common causes of high ALT:

Infections

Patients diagnosed with hepatitis, whether A, B, or C, typically have elevated ALT liver enzymes. Hence, if you got a test value exceeding the normal range of ALT and are showing hepatitis symptoms, consult your doctor to secure the proper diagnostic lab tests.

Aside from hepatitis, studies have also shown that those with infectious mononucleosis have elevated liver enzymes, including ALT. So your doctor may proceed to check for swelling in your tonsils and liver on top of common infection symptoms. 

Did you know? Hepatitis can be prevalent among older kids. That’s why it’s vital to detect hepatitis in children at the onset of the symptoms. This allows for better treatment and speedy recovery.  

Medications

Various drugs can cause high ALT levels, such as anti-seizure medications (phenytoin, valproic acid, carbamazepine, etc.), antidepressants, antipsychotics, cholesterol-lowering drugs, heparin therapy, acetaminophen, and many others. So if you’re taking these medications, make sure to let your doctor know. 

Herbal Supplement

Herbal teas and supplements can also elevate your ALT. These include kava, chaparral, ephedra, skull cap, comfrey tea, and Yohimbe. While traditional medicine may suggest that these supplements benefit your health, consult with your healthcare provider before taking them regularly.  

Alcohol and Toxins

Alcohol has been known to cause fatty liver tissues and induce inflammation. As a result, binge drinking elevates liver enzymes like ALT and causes gradual hepatic damage. Other substances like cocaine and poisonous liquid also increase ALT, as they generate high levels of hepatic toxicity.   

Diseases

Medical conditions associated with high ALT include hemochromatosis (iron overload), fatty liver disease, cirrhosis, thyroid disease, diabetes, Celiac disease, cancer, hemolysis, etc. Heart disease has also been associated with elevated ALT. 

If you have a family history of liver disease, there’s a higher chance of getting elevated ALT in your bloodwork, especially with an unhealthy lifestyle. So opt for a CMP 14 blood test to be included in your annual wellness checkup to detect liver problems early. 

What Should I Do if My ALT Is High? 

Seeing an elevated ALT in your test results can be alarming, especially if it’s far off the upper limit and if the other parameters also go beyond the normal range. But you can lower this liver enzyme (along with the others) through the following ways:

  1. Get Tested for the Cause of Increased ALT

Finding the root cause of your elevated ALT, whether it’s a disorder or a medication, is imperative for the right course of action in normalizing it. In addition, be mindful of symptoms you may have been experiencing, especially those related to liver problems. These could include abdominal pain and swelling, appetite loss, fatigue, dark urine, pale stool, vomiting, itchy and easily bruised skin, and jaundice (yellow eyes and skin). 

Your doctor will assess your symptoms and request appropriate liver function tests. Once the condition is diagnosed, you will be given proper treatment. You will most likely take another ALT test, among others, to see if you already have low ALT levels within the normal range. 

  1. Limit Cholesterol and Avoid High-Carb Foods

Changing your diet typically tops the lifestyle changes that improve your liver health. In the case of high ALT, shifting to a low carbohydrate diet has a beneficial impact on normalizing the liver enzyme’s production. 

In a 2015 study, high carbohydrate intake of fructose-rich food and beverages significantly increased ALT. On the other hand, a low-carb diet decreases the enzyme twice as a low-fat diet.  

While carbohydrates seem to trigger the spike in liver enzymes, fat, specifically bad cholesterol, doesn’t do any favor. High cholesterol overloads liver function, increases ALT, and even promotes the risk of liver cancer. That said, it’s best to avoid fatty foods such as whole-milk dairy, red meat, and those smothered in oil. 

Think you have high cholesterol? You will know for certain when you take the comprehensive lipid profile blood test. Doing so allows you to have a base record of your lipid levels, helping you assess your risk for heart and liver disease. 

  1. Drink a Cup of Coffee a Day

Coffee comes with plenty of health benefits. However, it can be subjective depending on your physical and mental state. But in the case of liver function, studies have shown that drinking coffee aids in preventing high serum ALT.

Moreover, a 2015 study says that drinking coffee reduces your risk for liver cancer and chronic liver disease, bordering cirrhosis. So secure one cup of coffee daily, especially in lieu of alcohol. If you have anxiety disorders, consult your doctor first, as too much coffee can aggravate the condition. 

  1. Be More Physically Active

Exercise promotes liver health and allows you to lose weight. By being physically active for about 30 minutes daily, you improve your metabolism, which involves the oxidation of fatty acids. This helps ease liver function and, by extension, prevents injuries that lead to increased liver enzymes in the blood. 

Consistent physical activity is particularly helpful for those with fatty liver. In a 2018 review, evidence shows that regular exercise aid liver functions in people with nonalcoholic fatty liver disease (NAFLD), from damage reduction to improved insulin resistance. 

  1. Avoid Alcohol and Smoking

It’s no secret that alcohol can cause severe liver damage if consumed habitually. Heavy drinkers are prone to alcoholic liver disease and alcoholic hepatitis. On top of that, alcohol is also the most significant risk factor for liver cirrhosis. 

Smoking is another habit you should shake off if you plan to lower your serum ALT. According to an article published in the Journal of Hepatology, cigarette smoking aggravates liver problems and contributes to the impediment of hepatic treatment. This remains true with secondhand smoke. 

If you’re having trouble leaving these unhealthy habits behind, seek help from professionals and support from your social circle. 

  1. Rethink Taking Supplements, Drugs, or Herbal Medicines

As herbal teas and vitamin supplements (iron and vitamin A) can cause liver toxicity, make sure to avoid them if you have elevated liver enzymes. Likewise, consult your doctor regarding taking prescribed medications and be sure not to take them beyond the recommended dosage. For example, acetaminophen (a drug for fever and pain) can induce acute liver damage if taken in large amounts. 

Other Frequently Asked Questions 

Which is worse: high AST or ALT?

Liver enzymes AST and ALT are often compared to better understand liver health. Getting high lab values for both AST and ALT indicates the severity of the liver problem. Generally, if AST is significantly elevated than an already high ALT, it could suggest cirrhosis, which can lead to liver failure. 

How quickly can ALT levels drop?

On average, ALT decreases significantly after treatment and lifestyle changes in about four weeks. This depends on how consistent you are with the necessary adjustments. For example, if you have given up alcohol, your ALT could start to drop in a week and continue to do so with continuous abstinence. 

Can ALT levels go down on their own?

Unless you change your diet, start exercising, and eliminate unhealthy habits like heavy drinking and smoking, serum ALT levels will not decrease. Additionally, if the elevation of the liver enzyme is due to a severe liver disorder, failing to address and avail of proper treatment will only contribute to high ALT remaining unchanged. 

Bottom Line 

When your ALT levels are elevated, it’s certainly high time to check your liver. Doing so allows you to seek proper treatment and employ the necessary lifestyle adjustments, such as changing your diet, getting tested for a particular disorder, and being physically active. If symptoms of liver damage are observed, consult your doctor immediately. 

Alanine transaminase (ALT) blood test Information | Mount Sinai

SGPT; Serum glutamate pyruvate transaminase; Alanine transaminase; Alanine aminotransferase





The alanine transaminase (ALT) blood test measures the level of the enzyme ALT in the blood.





























Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.


How the Test is Performed

A blood sample is needed.












How to Prepare for the Test

No special preparation is needed.












How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.












Why the Test is Performed

ALT is an enzyme found in a high level in the liver. An enzyme is a protein that causes a specific chemical change in the body.

Injury to the liver results in release of ALT into the blood.

This test is mainly done along with other tests (such as AST, ALP, and bilirubin) to diagnose and monitor liver disease.












Normal Results

The normal range is 4 to 36 U/L.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.












What Abnormal Results Mean

An increased ALT level is often a sign of liver disease. Liver disease is even more likely when the levels of substances checked by other liver blood tests have also increased.

An increased ALT level may be due to any of the following:

  • Scarring of the liver (cirrhosis)
  • Death of liver tissue
  • Swollen and inflamed liver (hepatitis)
  • Too much iron in the body (hemochromatosis)
  • Too much fat in the liver (fatty liver)
  • Lack of blood flow to the liver (liver ischemia)
  • Liver tumor or cancer
  • Use of drugs that are toxic to the liver
  • Mononucleosis (“mono”)
  • Swollen and inflamed pancreas (pancreatitis)












Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

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










Daniels L, Khalili M, Goldstein E, Bluth MH, Bowne WB, Pincus MR. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 22.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 73.

Last reviewed on: 2/28/2023

Reviewed by: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.


ALT and AST what is it?

ALT ( alanine aminotransferase) and AST (aspartate aminotransferase) – belong to aminotransferase enzymes involved in amino acid metabolism. They are also called liver enzymes. They are found mainly in the cells of the liver and in other organs: pancreas, heart, kidneys, muscle tissue. A small amount of ALT and AST may appear in the blood due to physiological processes. However, in case of liver diseases (infectious or toxic hepatitis, tumor), damage to the liver cells occurs, the permeability of cell membranes is impaired and a large amount of ALT and AST enzymes are released into the blood – as a result, a cytolytic syndrome develops.

ALT and AST transaminases are specific markers of liver disease. Indications for their appointment may be the following:

  • Presence of symptoms: nausea, vomiting, abdominal pain, yellowing of the skin and sclera, lethargy.
  • laboratory diagnostics of liver diseases: viral hepatitis A, B, C, toxic hepatitis, non-alcoholic fatty liver disease (steatohepatitis), alcoholic liver disease, cirrhosis of the liver.
  • Monitoring the dynamics of therapy for liver diseases.

Norms for the content of liver enzymes in the blood:

Age Men Women Units
0-1 years 13-45 U/ml
1-60 years old 10-40 7.0-35.0
60-90 years old 13.0-40.0 10.0-28.0
Over 90 years old 6. 0-38 5.0-24.0

Reasons for increasing ALT, AST (hepatic and extrahepatic)

Increase in ALT, AST Acute viral hepatitis (A, B, C, D, E, Epstein-Barr virus, cytomegalovirus) Hemolysis
Chronic hepatitis B, C Hypoxic hepatitis
Non-alcoholic fatty liver disease Decreased thyroid function
autoimmune hepatitis Intense physical activity
drug-induced hepatitis Macro-AST-emia syndrome
α1-antitrypsin deficiency celiac disease
Wilson’s disease
hereditary hemochromatosis

The level of ALT in acute viral or drug-induced hepatitis can rise 50 times or more. With steatohepatitis and alcoholic liver disease, the increase in ALT is moderate – no more than 5 times. In chronic hepatitis, there is an increase in ALT by about 7 times. In cirrhosis, ALT and AST values ​​increase by 3-5 times, while AST may be higher than ALT.

During pregnancy, a woman’s body experiences an increased load, so there may be a slight increase in transaminases.

Currently, macro-AST-emia syndrome has become known – this is a rare condition in which complexes are formed in the human body from the AST molecule and immunoglobulin. This condition may be hereditary or associated with liver disease. It is characterized by a prolonged and asymptomatic increase in alanine aminotransferase in the blood.

An important diagnostic value is not only an increase in the level of transaminases, but also a decrease. A decrease in ALT and AST below normal indicates end-stage cirrhosis or severe liver damage in hepatitis. This is an extremely unfavorable sign, as it indicates the total destruction of liver cells.

ALT (ALT, Alanine aminotransferase, alanine transaminase, SGPT, Alanine aminotransferase)

Alanine aminotransferase (AlAT, ALT) is an intracellular enzyme, the content of which in the blood of healthy people is low. It is mainly found in the cells of the liver, myocardium, skeletal muscles, pancreas. When cells containing ALT are damaged or destroyed, the enzyme is released into the bloodstream, and its concentration in the blood increases.

Determination of the level of alanine aminotransferase is carried out for the diagnosis of liver diseases and dynamic monitoring of their treatment. The analysis is performed for suspected acute or chronic hepatitis of viral or toxic etiology, cirrhosis of the liver, primary tumors, or metastatic liver disease.

The growth of alanine aminotransferase in the blood in hepatitis is noted much earlier than the onset of the icteric stage, which makes it possible to identify the pathology at the initial stage.

As part of a screening examination (preventive examination of persons who do not have complaints) to assess the state of the liver, before planned hospitalization and surgical treatment, an analysis for ALT is prescribed together with another enzyme – AsAT (aspartate aminotransferase).

The level of ALT along with other enzymes is evaluated in diseases of the pancreas and gallbladder – pancreatitis, cholecystitis, cholelithiasis; if there are complaints of unexplained general weakness, fatigue, yellowness of the skin and sclera, abdominal pain, including a feeling of heaviness in the right hypochondrium, nausea, vomiting.

In addition, the ALT level is taken into account in myocardial infarction and myocarditis, although in cases of heart damage it is only of secondary importance. The study is prescribed for suspected myositis, myodystrophy, when complaints of muscle pain cannot be explained by injuries or excessive physical activity.

Donation is a mandatory reason for testing for ALT.

ALT values ​​are assessed in any chronic disease, before prescribing drug therapy, for example, antitumor, anti-tuberculosis drugs, to assess the initial state of the liver and over time to assess drug tolerance.

Preparation for the procedure

It is better to take the test in the morning on an empty stomach (after an 8-14 hour break after the last meal).

Drinking water is allowed.

If necessary, it is permissible to donate blood 4-6 hours after a light meal.

On the eve it is desirable to avoid physical and emotional overload, overeating.

Avoid drinking alcohol 5-6 days before the test.

Avoid smoking 30 minutes before blood sampling.

Deadline

The survey is completed within one business day.

What can affect the results

Intense physical activity the day before and even a few days before the test can lead to damage to muscle tissue (the so-called tear of muscle fibers) and, accordingly, an increase in the level of ALT. For the same reason, the analysis given after the injury is not informative.

The use of alcohol, certain drugs (antibiotics, non-steroidal anti-inflammatory drugs, anticancer drugs, oral contraceptives, etc.) often distort the result of the study. The list of medications taken should be discussed with the doctor who ordered the analysis, cancel those that are possible – without risk to health.

ALT (ALT, Alanine aminotransferase, alanine transaminase)

For research, blood is taken from a vein. Usually, ASAT (AST, Aspartate aminotransferase) is determined simultaneously and the ratio of ASAT / AlAT (de Ritis coefficient) is estimated.

You can take a blood test for ALT (ALT, Alanine aminotransferase, alanine transaminase) at the nearest INVITRO medical office. The list of offices where biomaterial is accepted for laboratory testing is presented in the “Addresses” section.

Interpretation of test results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.

Normal

Units of measure: U/l.

Reference values ​​

Floor Age AlAT level, U/l
Both < 5 days < 49
5 days – 6 months < 56
6 – 12 months < 54
1 – 3 years < 33
3 years – 6 years < 29
6 – 12 years old < 39
Male 12 – 17 years old < 27
> 17 years old < 41
Female 12 – 17 years old < 24
> 17 years old < 31

Explanation of indicators

The level of ALT depends on the age and sex of the patient. Minor deviations from the norm, as a rule, do not require drug therapy, and the recommendations associated with them, such as rational nutrition, avoidance of alcohol, etc. should be discussed with your doctor.

The AST/ALAT ratio (de Ritis ratio) is normally between 0.91 and 1.75.

What do low readings mean

A significant decrease in the level of ALT can be detected in severe liver damage, for example, in the terminal stage of liver cirrhosis, when the number of liver cells is significantly reduced.

What do elevated indicators mean

First of all, with an increase in ALT, liver problems should be suspected: fatty hepatosis, hepatitis of viral or toxic etiology, cirrhosis of the liver, liver cancer – primary or metastatic.

The degree of increase in ALT is usually associated with the extent or severity of liver damage, but cannot be considered as a determining factor for the prognosis of the disease. The maximum levels of ALT (and AST) – more than a hundred times higher than the norm, are observed in patients with acute viral and drug-induced hepatitis.

A significant increase in alanine aminotransferase can be observed in acute cholecystitis, cholelithiasis, and acute destructive pancreatitis. Another reason may be the use of hepatotoxic drugs that damage liver cells.

An increase in the level of ALT is detected with extensive injuries of the skeletal muscles, severe myositis and myodystrophy, frequent intramuscular injections.

A less significant increase in ALT is recorded in acute myocardial infarction and myocarditis.

Additional examination in case of deviation of the indicator from the norm

If a change (often an increase) in the level of ALT is detected, patients are consulted

general practitioners

,

gastroenterologists

, hepatologists, infectious disease specialists.

To clarify the diagnosis, in addition to ALT, other liver enzymes (AST, gamma-HT, alkaline phosphatase, bilirubin), clinical blood counts, and markers of viral hepatitis, primarily hepatitis B and hepatitis C, are usually examined.

An ultrasound examination of the abdominal organs is performed, according to indications – computed tomography (CT) with contrast.

If damage to the skeletal muscles is suspected, the CPK enzyme is additionally examined and a rheumatologist is consulted.

If there is a suspicion of damage to the heart muscle, a consultation with a cardiologist is required. Usually, the doctor prescribes additional electrocardiography (ECG), echocardiography, blood test for CF-CF, troponin I.

O.P. The role of new reference values ​​of alanine aminotransferase in the diagnosis of various forms of non-alcoholic fatty liver disease in patients with metabolic syndrome. Journal of Biomedical Technologies № 1. 2015. P. 9-15.

  • Clinical guidelines “Cirrhosis and fibrosis of the liver”. Developed by: Russian Society for the Study of the Liver, Russian Gastroenterological Association. – 2021.
  • Clinical guidelines “Liver cancer (hepatocellular)”. Developed by: Association of Oncologists of Russia, Russian Society of Clinical Oncology, Russian Society of Radiologists and Radiologists.