9 causes of irregular periods

A woman’s menstrual cycle does not always arrive on exactly the same day every month. Periods can occasionally come earlier or later, and a single unusual cycle does not necessarily mean something is wrong. However, when periods repeatedly become unpredictable, unusually heavy, very light, widely spaced or stop altogether, there may be an underlying reason.

The menstrual cycle is controlled by a delicate interaction between the brain, ovaries, uterus and hormones. Changes affecting any part of this system can alter when ovulation occurs and, consequently, when menstrual bleeding happens. Irregular periods can be linked to conditions such as polycystic ovary syndrome (PCOS), thyroid disorders and reproductive health problems. Stress, major changes in weight, intense exercise and some medicines can also affect the cycle.

In this article, Tribune Online highlights nine possible causes of irregular periods and when medical attention may be necessary.

Pregnancy

Pregnancy is one of the first things to consider when someone who normally has periods suddenly misses one. A missed period can be an early sign of pregnancy. Some women may also experience light bleeding or spotting in early pregnancy, which can sometimes be mistaken for a period.

If pregnancy is possible and a period is late, taking a home pregnancy test is a reasonable first step. A healthcare professional can provide further testing if the result is unclear or symptoms continue. Pregnancy-related bleeding should not always be assumed to be harmless. Significant bleeding or severe abdominal or pelvic pain during pregnancy requires urgent medical assessment.

Polycystic ovary syndrome

Polycystic Ovary Syndrome , commonly called PCOS, is a hormonal condition that can interfere with normal ovulation. Women with PCOS may have periods that occur infrequently, arrive unpredictably or disappear for several months. Some may also experience acne, increased facial or body hair, thinning hair on the scalp or difficulty becoming pregnant.

PCOS does not only affect women who are overweight. It can occur in women of different body sizes. Because the condition can affect ovulation and hormone levels, persistent irregular periods should be assessed rather than simply accepted as a normal variation.

Thyroid disorders

The thyroid gland produces hormones that influence several processes in the body, including reproductive function. Both an underactive thyroid, known as hypothyroidism, and an overactive thyroid, known as hyperthyroidism, can affect menstrual cycles.

Hypothyroidism may be associated with heavier or less frequent periods, while hyperthyroidism can lead to lighter or less frequent bleeding.

Other symptoms may provide clues. Depending on the condition, these can include tiredness, changes in weight, sensitivity to cold or heat, changes in heart rate and alterations in mood.

A blood test can help determine whether a thyroid problem is contributing to menstrual changes.

ALSO READ: 5 health benefits of swimming

Major changes in body weight

A significant change in weight can affect the hormones involved in ovulation. Rapid weight loss, particularly when a person is not consuming enough energy, can cause periods to become irregular or stop. This can happen when someone follows an extreme diet or loses a substantial amount of weight over a short period.

Weight gain can also affect menstrual regularity in some women. It may worsen insulin resistance and contribute to hormonal changes associated with PCOS. This is one reason crash diets are not a good approach to weight management. Where weight is affecting menstrual health, gradual and sustainable changes in eating habits and physical activity are generally more appropriate than extreme restriction.

Excessive exercise

Regular exercise is good for health, but very intense training combined with inadequate food intake can interfere with normal reproductive function. When the body does not have enough energy to support its needs, ovulation may become less frequent or stop. Menstrual periods may then become widely spaced or disappear.

This can occur in women involved in intensive sports or demanding exercise programmes, particularly when low energy intake is also present. Long periods without menstruation should not be ignored. Reduced oestrogen levels associated with prolonged disruption of ovulation can affect bone health. Women who exercise heavily and notice that their periods have become irregular or stopped should speak with a healthcare professional.

Stress and major life changes

Significant emotional or physical stress can affect the hormones responsible for ovulation.

Work pressure, examinations, relationship difficulties, bereavement, illness and major changes in daily routine can all affect the body. Poor sleep may add to the problem. For some women, the result may be a late period. In more significant cases, menstruation may temporarily stop.

However, not every irregular period should be blamed on stress. If the problem continues, other causes such as pregnancy, PCOS or thyroid disease should also be considered.

Persistent changes deserve proper assessment rather than repeated assumptions that stress is responsible.

Perimenopause

As women approach menopause, hormone levels naturally begin to fluctuate. This transition is called perimenopause . It usually occurs in the years before menopause and can cause noticeable changes in the menstrual cycle. Periods may become shorter or longer, heavier or lighter, or occur less frequently. Some women may skip several periods before menstruating again.

Other symptoms can include hot flushes, night sweats, sleep difficulties and changes in mood.

Menopause itself is reached after 12 consecutive months without a menstrual period, provided there is no other explanation for the absence of periods. The timing of perimenopause varies from woman to woman. New or unusual bleeding during this stage should still be discussed with a healthcare professional, particularly if it is very heavy or occurs after menopause has been established.

Medicines and hormonal contraception

Some medicines can affect menstrual bleeding.

Hormonal contraceptives, including pills, injections, implants and hormonal intrauterine devices or systems, can change the usual pattern of menstruation. Depending on the method, a woman may experience spotting, lighter periods, changes in cycle timing or no bleeding at all.

These changes do not necessarily mean that contraception is harmful. However, unexpected or troublesome bleeding should be discussed with a healthcare professional. Some medicines that are not contraceptives can also affect menstrual cycles. Anyone who notices a change after starting a new medicine should discuss it with a doctor or pharmacist rather than stopping the medicine without advice.

Conditions affecting the uterus or ovaries

Problems involving the reproductive organs can also cause irregular or unusual bleeding.

Uterine fibroids, for example, can cause heavy or prolonged periods and may sometimes affect the regularity of bleeding. Fibroids are non-cancerous growths in or around the uterus and are relatively common. Ovarian cysts can sometimes affect the menstrual cycle, although many cysts cause no symptoms and disappear without treatment.

Other conditions, including endometriosis, adenomyosis and uterine polyps, may also cause abnormal bleeding or pelvic symptoms.

Depending on the symptoms, a healthcare professional may recommend a pelvic examination, blood tests or an ultrasound scan to investigate the cause.