The normal length of a woman’s menstrual cycle is 28 days, but this varies between individuals. Irregular menstruation is when the length of the cycle is more than 35 days, or if the duration varies.
A period, or menstruation, is the part of the menstrual cycle in which the endometrium, which is the lining of the uterus, is shed. This appears as bleeding from the womb that is released through the vagina.
Irregular periods, also called oligomenorrhea, can occur if there is a change in contraception method, a hormone imbalance, hormonal changes around the time of the menopause, and endurance exercises.
Treatment for irregular periods during puberty and around the menopause is not usually necessary, but if irregular periods occur during the reproductive years, medical advice may be necessary.
A menstrual cycle lasts around 28 days, but it can vary from 24 days to 35 days, depending on the individual.
Most women have between 11 and 13 menstrual periods each year. Bleeding usually lasts around 5 days, but this too can vary, from 2 to 7 days.
When menstruation first starts, it can take up to 2 years to establish a regular cycle. After puberty, most women’s menstruation is regular. The length of time between each period is similar.
However, for some women, the time between periods and the amount of blood shed vary considerably. This is known as irregular menstruation.
The main symptom of irregular menstruation is when the cycle is longer than 35 days, or if it varies in length.
If there are changes in blood flow, or if clots appear that are more than 2.5 centimeters in diameter, this is also considered irregular.
A number of factors increase the chance of irregular menstruation. Most relate to hormone production. The two hormones that impact menstruation are estrogen and progesterone. These are the hormones that regulate the cycle.
Life cycle changes that influence the hormonal balance include puberty, menopause, pregnancy, and childbirth, and breastfeeding.
During puberty, the body undergoes major changes. It can take several years for the estrogen and progesterone to reach a balance, and irregular periods are common at this time.
Before menopause, women often have irregular periods, and the amount of blood shed may vary. Menopause occurs when 12 months have passed since the woman’s last menstrual period. After the menopause, a woman will no longer have periods.
During pregnancy, menstruation ceases, and most women do not have periods while they are breast-feeding.
Contraceptives can cause irregular bleeding. An intrauterine device (IUD) may cause heavy bleeding, while the contraceptive pill can cause spotting between periods.
When a woman first uses the contraceptive pill, she may experience small bleeds that are generally shorter and lighter than normal periods. These usually go away after a few months.
Other changes that are associated with irregular periods include:
- extreme weight loss
- extreme weight gain
- emotional stress
- eating disorders, such as anorexia or bulimia
- endurance exercise, for example, marathon running.
A number of disorders are also linked to missed or irregular menstruation.
Irregular periods can sometimes indicate a health problem, and some of these can lead to further problems, such as fertility issues.
Polycystic ovarian syndrome (PCOS) is a condition in which a number of small, fluid-filled sacs known as cysts develop in the ovaries.
Women with PCOS have unusually high levels of the male sex hormone, androgen, or testosterone.
According to the Office on Women’s Health at the United States Department of Health and Human Services, PCOS affects between 10 percent and 20 women of reproductive age, or up to 5 million American women. Girls as young as 11 years old have been diagnosed with PCOS.
A thyroid disorder can cause irregular periods. The thyroid gland produces hormones that affect the body’s metabolism.
Cervical or uterine cancer, or cancer of the womb, may, in rare cases, cause bleeding between periods or during sexual intercourse.
Endometriosis is a condition in which cells that are normally found inside the uterus, called endometrial cells, grow outside it. In other words, the lining of the inside of the uterus is found outside of it.
Endometrial cells are the cells that shed every month during menstruation, so endometriosis is most likely to affect women during their childbearing years.
The cellular growth involved in endometriosis is not cancerous. There may be no symptoms, but it can be painful, and it can lead to other problems. If released blood gets stuck in surrounding tissue, it can damage the tissue, causing severe pain, irregular periods, and infertility.
Pelvic inflammatory disease (PID) is an infection of the female reproductive system. Among women, it is the most common and serious complication of sexually transmitted infections (STIs), apart from AIDS.
If detected early it can be treated with antibiotics, but if it spreads, it can damage the fallopian tubes and the uterus, resulting in chronic, or long-term, pain. There are many symptoms, and they including bleeding between periods and after sex.
Maintaining a healthful lifestyle can help reduce the risk of some of the causes of irregular periods.
- exercising regularly to maintain a healthy weight and reduce stress
- following a healthful diet
Some herbal remedies, such as black cohosh, chasteberry, licorice root, and turmeric are all said to help, but research has not confirmed their effectiveness, and they may have adverse effects. It is better to speak to a doctor first.
Treatment, if needed, will depend on the cause.
Puberty and menopause: Irregular periods that occur during puberty or as the woman approaches menopause do not usually need treatment.
Birth control: If irregular bleeding is due to contraception, and it continues for several months, the woman should talk to a health care professional about other options.
PCOS and obesity: In cases of PCOS, overweight, or obesity losing weight may help stabilize menstruation. A lower weight means the body does not need to produce so much insulin. This leads to lower testosterone levels and a better chance of ovulating.
Thyroid problems: Treatment for the underlying problem is likely to be prescribed. This may include medication, radioactive iodine therapy or surgery.
Stress and eating disorders: Psychological therapy may help if emotional stress, an eating disorder, or sudden weight loss have triggered irregular periods. This may include relaxation techniques, stress management, and talking to a therapist.
A low-dose birth control pill that containing a combination of estrogen and progesterone may help. This will decrease androgen production and will help to correct abnormal bleeding.
Alternatively, taking progesterone for 10 to 14 days each month is likely to regulate the periods.
Irregular periods can indicate a problem with fertility, but this is not always so. Ovulation can occur, even while menstruation is irregular.
Here are some things you can do to track ovulation:
- Mark any periods on a calendar, and look for patterns.
- Check for changes in cervical mucus. As ovulation approaches, the mucus will be more plentiful, slippery, clear, and stretchy.
- Take your temperature each day and note when it spikes. This can indicate that ovulation is occurring.
If irregular periods are linked to fertility problems, these records will help a doctor reach a diagnosis.
Anyone who is concerned about irregular menstruation should seek medical advice.