Irregular periods – NHS

Irregular periods are not usually a sign of a problem. But speak to a GP if your periods are irregular or your normal pattern of periods changes.

Check if you have irregular periods

The average gap between periods starting (the menstrual cycle) is 28 days. It can sometimes be a bit shorter or longer.

A woman’s periods are irregular if the gap between them is less than 21 days or more than 35 days.

Irregular periods can affect anyone who has periods.

It’s more likely for your periods to be irregular when they first start during puberty, and when you’re nearing menopause.

Keeping track of your periods

Using an app or a diary to keep track of your periods can help you see if they’re irregular.

Day 1 of your menstrual cycle is the first day of your period. The last day of your cycle is the day before your next period.

Causes of irregular periods

Common causes of irregular periods include:

• puberty, when you start your periods
• the start of menopause (usually between the ages of 45 and 55)
• pregnancy – a missed period is often an early sign of pregnancy
• hormonal contraception like the progestogen-only pill, contraceptive injection and intrauterine system (IUS)
• losing or gaining a lot of weight
• stress and anxiety
• exercising too much

Sometimes, conditions like polycystic ovary syndrome (PCOS) and an underactive thyroid gland can cause irregular periods.

Non-urgent advice: See a GP if:

• your periods are irregular
• your periods last longer than 7 days
• you have irregular periods and other symptoms like weight gain, tiredness, hair growth on your face and dry or oily skin
• your periods are irregular and you’re struggling to get pregnant

Treatments for irregular periods

Treatment is not always needed for irregular periods.

The GP may refer you to a specialist (gynaecologist) if you need tests to find out what’s causing your irregular periods. If treatment is needed it will depend on the cause.

For example, if a condition like polycystic ovary syndrome is causing irregular periods, the combined pill may help make your periods more regular.

Trying for a baby

Getting pregnant can be more difficult if you have irregular periods because you might not release an egg (ovulate) regularly.

It can help to have sex every 2 or 3 days throughout your cycle without using contraception.

If you’re struggling to get pregnant, hormone medicine or fertility treatment may be recommended.

Read more about trying to get pregnant.

Video: Menstrual cycle

This animation explains in detail how the menstrual cycle works.

Media last reviewed: 21 October 2020
Media review due: 21 October 2023

Page last reviewed: 26 July 2022
Next review due: 26 July 2025

Irregular periods: Causes, pregnancy, and more

It is normal for a person’s menstrual cycle to vary slightly in length, resulting in irregular periods. Other causes of irregular periods include stress, medications, and various health conditions.

If someone’s menstrual cycle is shorter than 24 days, more than 38 days long, or if the length varies significantly from month to month, they have irregular periods. Doctors call this oligomenorrhea.

It is normal for the menstrual cycle length to vary slightly from month to month, especially if someone is going through puberty, breastfeeding, or approaching menopause.

Many other factors can affect period regularity, too, such as stress, medications, and mental or physical health conditions.

In this article, learn more about irregular periods, including the causes and treatment.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Irregular periods, or oligomenorrhea, can occur for many reasons. Many relate to hormone levels.

Estrogen, progesterone, and follicle-stimulating hormone are the main hormones responsible for regulating the menstrual cycle. If something disrupts or alters how these hormones rise and fall each cycle, it can cause irregular periods.

Occasional irregular periods are common and are not usually cause for concern. Factors that may contribute to irregular periods include:

• natural hormonal shifts
• hormonal birth control
• stress
• endurance exercise
• weight loss

More persistent irregularity may be a sign of an underlying condition.

The following sections look at some of the potential causes for irregular periods in more detail.

During puberty, the body undergoes significant changes. It can take several years for the hormones that regulate periods to fall into a reliable pattern. During this time, it is common to have irregular periods.

Oligomenorrhea can also occur after childbirth and while breastfeeding until the hormones return to normal after having a baby.

Breastfeeding, especially exclusive and frequent breastfeeding, can suppress ovulation, causing a person’s periods to stop. Doctors call this lactational amenorrhea.

Periods also become irregular during perimenopause, which is the first stage of menopause. During this time, hormone levels begin to fall. Periods may get further and further apart until a person stops having them entirely.

Learn about premenopause and perimenopause here.

Hormonal birth control works by stopping ovulation. This means a person does not have a true period while they are using it. Instead, some people have no period at all, while others will have withdrawal bleeds that can seem similar to a period.

When a person first starts the pill, patch, implant, or hormonal intrauterine device (IUD), they may experience irregular bleeding during the first few months. This may become more regular as time goes on or stop entirely.

Similarly, when a person stops using hormonal birth control, this can also lead to irregular periods. It takes time for the body’s hormonal cycle to begin working as usual again.

Typically, people have a withdrawal bleed 2–4 weeks after stopping birth control pills. The next bleed is a period. It can take up to 3 months for the cycle to settle into a regular pattern.

People who had irregular periods before they began hormonal birth control may return to having an irregular cycle after they stop using it.

Irregular periods can sometimes indicate a health condition, such as:

Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a condition where small, fluid-filled sacs, known as cysts, develop in the ovaries. PCOS causes high testosterone levels, which can prevent or delay ovulation and a person’s period.

The other symptoms of PCOS include:

• acne
• excessive hair growth
• insulin resistance that may affect weight
• depression
• trouble getting or staying pregnant

Learn more about the symptoms of PCOS here.

Eating disorders

Eating disorders, such as anorexia nervosa, bulimia nervosa, and binge eating disorder, can cause absent or irregular periods. This is more likely to occur if someone has experienced severe weight loss.

The signs of an eating disorder can include:

• extreme restriction of food or calorie intake
• cutting out whole food groups from the diet unnecessarily, such as carbohydrates
• fasting, followed by binge eating
• going to the bathroom immediately after meals
• eating large amounts of food when not hungry

People who exercise excessively may also experience irregular periods. When people find it hard to stop exercising, it is known as compulsive exercise.

Learn the signs of an eating disorder here.

Endometriosis

Endometriosis is a condition in which cells that usually grow inside the uterus grow outside of it. These cells make up the uterine lining, which thickens and sheds with each menstrual cycle.

When the cells grow elsewhere, this cyclic thickening and shedding cause significant pain. Other symptoms include:

• heavy periods
• passing large blood clots
• bleeding between periods
• problems getting pregnant

Learn more about endometriosis and infertility here.

Thyroid disease

The thyroid produces hormones that affect metabolism, heart rate, and other basic functions. It also helps control the timing of ovulation and periods.

People with hyperthyroidism produce too much thyroid hormone, while those with hypothyroidism do not produce enough.

Thyroid disease can make periods heavy or light and can make them more or less frequent. It can also cause ovulation to stop in some people.

Symptoms of hyperthyroidism include:

• anxiety
• racing heart
• trouble sleeping
• irregular periods
• feeling hot
• unexplained weight loss, or sometimes, weight gain

Symptoms of hypothyroidism include:

• fatigue
• unexplained weight gain or sometimes, weight loss
• irregular periods or infertility
• dry skin
• cold sensitivity
• depression
• hair loss

Thyroid disease is treatable. An underactive thyroid may require thyroid hormone, while radioactive iodine may help with hyperthyroidism. Some types of thyroid dysfunction require the removal of the thyroid.

Other conditions

Other health conditions associated with irregular periods include:

• type 1 diabetes
• Cushing’s syndrome
• primary ovarian insufficiency
• congenital adrenal hyperplasia
• hormone-secreting tumors

Irregular periods are usually not harmful. However, persistent or long-term irregularity may raise the risk of other conditions, such as:

• Iron deficiency anemia: Blood contains iron. If periods are heavy or frequent, a person may lose enough blood to cause an iron deficiency.
• Infertility: Irregular periods can result from anovulation, which is when the body does not release an egg. This can mean a person has difficulty getting pregnant.
• Osteoporosis: Ovulation is a source of estrogen, which helps to keep the bones strong. If a person often does not ovulate, they may be at a higher risk for osteoporosis due to having less estrogen.
• Cardiovascular disease: Similarly, a lack of estrogen can raise the risk of cardiovascular disease.
• Endometrial hyperplasia: If a person has irregular periods for a long time without treatment, it may raise the risk for endometrial hyperplasia, which is when the uterus lining becomes unusually thick. This increases the risk of endometrial cancer.

Learn more about the importance of period symptoms here.

Having irregular periods from time to time is common and does not require treatment. Irregularity due to puberty, perimenopause, or contraception also does not typically require treatment.

However, someone may want to speak with a doctor if:

• the irregularity is persistent and has no apparent cause
• irregular periods could be related to a medication or health condition
• irregular periods occur alongside other symptoms, such as pelvic pain
• the person wants to get pregnant

If there is an underlying cause, a doctor will be able to diagnose it. Treatment will depend on what is causing the irregularity.

The potential treatment recommendations may include:

• Hormone therapy: Birth control that contains the hormones estrogen and progesterone can help raise hormone levels, which can counteract the effects of not ovulating. It can also make bleeds regular and easier to manage or reduce the symptoms of conditions such as PCOS, which may improve quality of life.
• Reaching a moderate weight: Both a lack of body fat and having excess body fat can impact menstruation. For those with PCOS who have higher body weight, maintaining a healthy weight can lower insulin levels. This leads to lower testosterone levels and an increased chance of ovulating.
• Nutritional therapy: If a person wants to lose or gain weight or has an underlying condition that affects their nutrition, they may benefit from help from a dietitian. They can help a person understand the type of diet that will help with their unique circumstances and support hormone health.
• Mental health treatment: If irregular periods are related to stress, anxiety, depression, or an eating disorder, a doctor may recommend psychological support. For many, this usually involves talk therapy with a psychologist. A multidisciplinary team will help with regular therapy, nutritional counseling, and support groups for those with eating disorders. People with severe underweight may need treatment in the hospital.
• Additional medications: Depending on the underlying cause, people with irregular periods may benefit from certain medications. For example, a doctor may prescribe metformin for people with PCOS. This is an insulin-lowering oral drug for type 2 diabetes, which can help ensure ovulation and regular periods.

Learn whether home remedies can help regulate periods here.

Irregular periods can sometimes make it more difficult to get pregnant, as the times a person is ovulating may also be irregular. People who skip periods may also have months where they do not ovulate.

However, this does not mean that pregnancy is impossible. Tracking when someone is ovulating can help. Try:

• Tracking periods: Mark any periods on a calendar, and look for patterns. Period tracking apps can help with pinpointing the time of likely ovulation. Ovulation almost always occurs about 2 weeks before a person’s period. However, the length of time between the start of the period and the next time a person ovulates can vary.
• Monitoring cervical mucus: As ovulation approaches, the cervical mucus will be more plentiful, slippery, clear, and stretchy.
• Measuring body temperature: Use a thermometer to measure body temperature first thing each morning and note when it spikes. This can indicate that someone has ovulated.
• Using ovulation predictor kits: These products test for a surge in luteinizing hormone, which suggests ovulation is imminent. A person has likely ovulated if there is a prolonged increase in morning body temperature after a positive ovulation test.

If these methods do not help, speak with a fertility doctor about irregular periods. They will be able to provide advice on what to do next.

Learn more about irregular periods and pregnancy here.

Irregular periods and occasional variations in cycle length are normal. However, if a person regularly has very short or long cycles, something may be affecting their menstrual cycle.

Temporary causes for irregularity can include stress, natural hormonal changes, and starting or stopping birth control.

Certain medications and health conditions can also cause irregular periods. If this is the case, a doctor will be able to diagnose it and provide treatment recommendations.

People with irregular periods who want to get pregnant may benefit from tracking when they ovulate or speaking with a fertility specialist.

Which periods are considered irregular? Women’s Health Education Portal Women First

The menstrual cycle is considered to be a kind of biological clock of the body. Regularity
menstruation is the most noticeable outward manifestation of a normal menstrual cycle. In the absence of
fertilization and attachment of the fetal egg, endometrial rejection occurs, which manifests itself
the onset of menstruation. It begins as a result of changes in the concentrations of steroid hormones.
in the ovaries, which are under the control of the pituitary and hypothalamus.

Irregular periods may indicate a deterioration in the psychological, physical condition
women
and even about the presence of various diseases. Violation of the cycle is a good reason to see a doctor.

In order to understand the various disorders of the menstrual cycle, you must first learn the basic
concepts of the physiology of the menstrual cycle.

physiology of the menstrual cycle

Irregular periods may indicate a deterioration in the psychological, physical condition
women and even about the presence of various diseases. Violation of the cycle is a good reason to see a doctor.

In order to understand the various disorders of the menstrual cycle, you must first learn the basic
concepts of the physiology of the menstrual cycle.

The essence of normal menstruation is monthly rejection and subsequent recovery.
structures of the endometrium (the lining of the uterus). This is the so-called uterine cycle. It consists of 3 phases
and includes menstruation itself, the proliferative phase in which growth and thickening occurs
functional layer of the endometrium for 14 days, and a secretory phase that coincides with the development
corpus luteum in the ovary and prepares the endometrium for implantation of the ovum in case of fertilization
eggs, continues until the 28th day. Such changes in the uterus occur synchronously with the ovarian
cycle, which includes the processes of maturation of the dominant follicle, ovulation (exit
eggs) and the formation of the corpus luteum, which helps maintain the appropriate hormonal levels
in case of pregnancy. If pregnancy does not occur, the corpus luteum undergoes reverse
development and menstruation appears, which heralds the end of one menstrual cycle and the beginning
next. All links of these chains are controlled by hormones.

A normal menstrual cycle lasts 28 days and menstrual bleeding usually lasts 4-6 days.
days.

In fact, only 15% of women have a cycle that lasts exactly 28 days. Any cycle lasting from 21 to 35
days is considered normal, and its length is individual and may not be the same for different women.

The longest menstrual cycles are observed immediately after puberty and for 5 years
before menopause, since during these periods the probability of not ovulating is the highest.

The following cycle fluctuations are considered acceptable:

First year after menarche
23-90 days

Fourth year
24-50 days

Seventh year
27-38 days

A regular menstrual cycle is established no earlier than 19-20 years, while the formation period is in progress
reproductive function and the establishment of the process of ovulation.

Normally, the menstrual cycle is biphasic and between two phases (approximately on day 14 with a 28-day cycle)
a rupture of the dominant follicle occurs with the release of an egg from it, ready for fertilization. Many
women feel this event with discomfort or short-term pain in the lower sections
belly left or right
in the middle of a cycle. The nature of vaginal discharge in the middle of the cycle also changes – they become
transparent, more plentiful and “viscous”. Before the next menstruation, there may be
feeling of engorgement
and swelling in the mammary glands.

If you have previously experienced such sensations and noticed changes in the vaginal secretion and general condition
organism depending on the phase of the menstrual cycle, and then they stopped noticing such manifestations,
worth paying attention to.

The duration of menstrual bleeding can also vary from 2 to 7 days. The most abundant
bleeding is observed on the 1st or 2nd day of menstruation. The normal amount of menstrual blood loss is
an average of 30 ml. Blood loss exceeding 80 ml is considered excessive. This amount is set
arbitrarily – this is the threshold at which, in the absence of treatment,
Iron-deficiency anemia.

The nature of menstruation is actually individual for each woman. It may change during
life. After the establishment of menstruation before the first pregnancy, the cycle can have one length and
duration of menstrual bleeding. With the onset of sexual activity or after childbirth, these parameters
may change.

To understand if changes in the menstrual cycle are normal, you should observe it for
minimum
3 months and mark all changes in a special calendar. Moreover, when new
cycle parameters, you need to remember if the woman has recently taken any medications, not
did you endure stress, a long flight with acclimatization and take into account all possible factors that could
influence the cycle.

How to understand that the cycle has become irregular?

Usually the appearance of menstrual cycle failures or the addition of additional new symptoms when
stably regular menstruation does not go unnoticed by a woman. What should you pay attention to
Special attention? Warning signs that indicate problems with the cycle:

• No cycle phase separation
• Duration less than 21 or more than 35 days
• Duration of menstrual bleeding less than 2 or more than 7 days
• Blood loss less than 50 or more than 150 ml for the entire cycle
• Volume of blood loss per day of menstruation more than 80 ml
• Onset of pain or other symptoms
• Deterioration of general condition

Menstrual disorders

Gynecology

Today, menstrual disorders are one of the most common gynecological abnormalities. Almost all women experience this at least once in their lives. But one thing is a “random” failure caused by stress, another thing is constant delays. In women born and raised in our latitudes, the first menstruation occurs, as a rule, from 12 to 13.5 years. During the first year, the cycle is established. And yet in this first year at least 8 cycles must pass. If, after the age of 14, menstruation has not yet begun, the girl needs an examination.

The duration of the cycle is counted from the beginning of one menstruation to the beginning of the next: a minimum of 21 days, a maximum of 35. A serious problem is a delay of 14 days or more (sometimes up to 6 months). There are also reverse situations when menstruation, on the contrary, comes too often. On the other hand, if for many years the cycle was 21-22 days, and then suddenly became longer, this is also an alarm. It is worth paying attention to the duration of the discharges themselves: for example, if from five to seven days this process has been reduced to two or three.

So, menstruation can be:

Painful. Often, pain in the lower abdomen and severe spasms are provoked by prostaglandins – biologically active substances that cause the uterine muscle to contract to remove blood. It is believed that after childbirth, such pains become weaker. If menstruation becomes painful after 35 years, then you should be wary, as these pains may have an organic cause: endometriosis, polyps, or uterine fibroids. Consult a gynecologist, he will determine the true cause of the pain.

Abundant When you change your pads or tampons every two hours, your blood comes out in large clots or your period lasts more than a week. In both young girls and women approaching menopause, such periods are the result of a hormonal imbalance and are easily corrected if you see a doctor. If the periods become too heavy, then this may indicate gynecological inflammation. The coil can also cause excessive bleeding. In this case, you need to tell your gynecologist about it. Now there are spirals, the use of which eliminates these problems.

Scanty when the bleeding is very slight and lasts only one to three days. This sometimes happens when taking birth control, at the beginning of menopause, or due to a sudden change in weight that provokes a slight hormonal disorder. But if your periods began to pass with light bleeding after abortion , diagnostic curettage of the uterus or curettage after childbirth, then you need to see a doctor. Sometimes this is a consequence of fusion (gluing) of the walls of the uterus, in which case a small surgical intervention may be necessary.

Irregular. “Standard” periods come every 28 days, with a difference of 24-48 hours. Both a shorter cycle (25 days) and a longer one (30-32 days) are not abnormal. Only if the cycle becomes either short or long, or lasts less than 25 days or more than 35 days, we can talk about irregular periods. In young girls, the regularity of the cycle is most often established one to two years after the first menstruation. So don’t worry. In the premenopausal period, before the ovaries completely stop working, periods can also become very capricious. In other cases, irregular periods most often indicate a lack of ovulation or its violation.

Absence of menstruation. What is the reason for – pregnancy, early menopause, hormonal or psychological problems, only a doctor will determine, sometimes after a series of studies and analyzes. The absence of menstruation is by no means normal.

Menstrual disorders include:

• absence of menses (amenorrhea),
• too frequent or too infrequent menstruation (oligomenorrhea),
• painful menstruation (dysmenorrhea, algomenorrhea),
• excessive menstruation (hypermenorrhea, menorrhagia),
• occurrence of intermenstrual uterine bleeding,
• development in a woman of the so-called premenstrual syndrome (PMS)

The most common causes of menstrual irregularities are:

1. The most common and most banal cause of failures is infection of the pelvic organs. Therefore, first of all, it is necessary to be examined and, if necessary, to carry out treatment. And if the reason was only in the infection, then the cycle will be restored.

2 . The situation is much more complicated if the irregularity of the cycle is caused by hormonal disorders , which can occur at different levels of hormone formation. A certain list of them has been scientifically confirmed, which is checked if this cause of cycle disorders is suspected. The general examination plan also includes a study of the function of the thyroid gland and adrenal glands , , and violations here can be associated with both their hyperfunction and decreased activity.

3 . Previous rubella and chickenpox can affect the laying of follicles in the ovary, and then violations occur from the very first cycles. The difficulty is that adolescents themselves rarely pay attention to this, and such disorders are diagnosed much later.

4. It happens that the follicular apparatus is genetically incorporated in such a way that a woman will have cycle disorders all her life, such as, for example, with polycystic ovaries.

5. And finally, quite often cycle disorders are caused by a whole range of reasons – both hormonal, inflammatory and others.

REMEMBER! Violations of the cycle should never be ignored, because, being not only a signal of existing health problems, they can also lead to very serious diseases. Self-diagnosis here is elementary – it is only important to notice any deviations in time and contact a qualified gynecologist. First of all, cycle disorders are associated with the risk of developing uterine tumors , such as fibromyoma, as well as ovarian cysts . Disorders such as endometrial hyperplasia ( thickening of the inner layer), polyps may occur.

If they are not surgically removed and left untreated for more than 5 years, there is a greater than 20% risk of cancer .