Back

What is menstruation?

Menstruation - having periods - is part of the female reproductive cycle that starts when girls become sexually mature at the time of puberty. During a menstrual period, a woman bleeds from her uterus (womb) via the vagina. This lasts anything from three to seven days. Each period commences approximately every 28 days if the woman does not become pregnant during a given cycle.

Why do women menstruate?

Menstruation is a very complicated process involving many different hormones, the woman's sex organs and the brain.

A woman's internal sex organs consist of two ovaries, the Fallopian tubes, the uterus (womb) and the vagina. The ovaries contain the eggs with which the woman is born and, during each period, a single egg will usually ripen and mature due to the action of hormones circulating in the bloodstream. When the egg is mature it bursts from the ovary and drifts through the Fallopian tube down into the uterus. The lining of the uterus - the endometrium - has been thickened by the action of hormones and made ready to receive the fertilised egg.

If the egg is fertilized and the woman becomes pregnant, it will fasten itself onto the endometrium. If the egg is not fertilized, however, resultant hormonal changes cause the endometrium to slip away and menstruation begins. Menstrual discharge is composed of the endometrium itself, together with a little fresh blood caused by the breaking of very fine blood vessels within the endometrium as it detaches itself from the inside of the uterus. The amount of blood lost due to the normal monthly period is usually less than 80mls.

When does menstruation begin?

These days, girls begin to menstruate when they are about 10 to 14 years-old. The average age is approximately 12. Women will continue to menstruate until the age of 45 to 55, when menopause begins. A woman will have approximately 500 periods in her lifetime.

Can you feel ovulation?

Ovulation usually takes place roughly 14 days after the first day of the start of a period; however, the exact timing can vary greatly from woman to woman. Some women know when they are ovulating because they can feel a slight pain in their lower abdomen. Other women may bleed slightly in the middle of their cycle.

Vaginal discharge also changes at ovulation. It increases in amount and becomes more watery due to hormonal changes. This is one of the ways that women who wish to practice natural family planning (NFP) using the mucus test can find out whether it is safe to have sex or not.

Women who do not experience such symptoms during ovulation can find out when they are ovulating by taking their temperature. This will rise by 0.5 degrees Celsius when ovulation occurs. To measure temperature effectively, it must be taken at the same time every morning before getting out of bed. Temperature readings taken from different parts of the body such as the mouth, under the arm, in the ear or in the rectum will all give a slightly different measurement. For this reason, it is important to choose one location and stick to it. When checking for temperature, rises can occur for a variety of reasons and, therefore, should not be used as the only method of detecting ovulation.

What influences menstruation?

As described above, menstruation is a very complex process involving many different hormones, the sexual organs and the nervous system.

First and foremost, hormones influence menstruation. If they are not in balance, the cycle will similarly be affected. If a woman's periods are very irregular, she can ask her doctor to measure the hormones in her blood to find out if her hormones are out of balance. This will give a rough indication as to whether there is a serious hormonal problem. However, since what is 'normal' varies greatly with regard to women's hormones, blood tests are not a particularly good measure of what can be considered much more subtle imbalances in a woman's cycle.

Weight also influences hormonal balance and menstruation. If a woman is underweight, her hormones will stop working properly and her periods might stop altogether. Recent research has also shown that obesity can throw hormones out of balance and make it harder for women to conceive. Stress also affects the hormones. Many women find that if they are worried about something, it can influence menstruation. In some cases, a woman's period might actually stop if she is very worried about whether she is pregnant.

Regular exercise and keeping fit and healthy can help regulate the menstrual cycle. On the other hand, exercising too much and overstressing the body can have a negative effect on the hormones to the extent that menstruation may cease.

What are the symptoms of painful periods?

The degree of discomfort experienced during menstruation varies from woman to woman. Some are never bothered by their periods, while others can be badly affected by unpleasant symptoms. These may include:

• pains in the abdomen
• pain in the vagina
• feeling nauseous and generally unwell
• diarrhoea
• sweating
• fatigue.

What can women do to relieve their symptoms?

There are several things that will help relieve discomfort:

• while menstruating, refrain from drinking caffeinated drinks such as coffee, tea, cola or cocoa.
• avoid stress. Relaxation and massage can work wonders.
• exercise and staying fit can help prevent painful periods.
• keep your abdomen warm.
• finally, use pain-relieving medicines if necessary.

Remember that it is always best to consult your doctor about your specific concerns.

What causes painful periods?

There is no single proven theory, but there are several possible reasons:

• contractions of the uterus similar to those felt in childbirth due to the hormone prostaglandin.
• the pain can be caused by the cervix dilating when the blood and the tissue are passed out of the womb.
• the pain can be due to earlier infections or inflammations of the uterus, or benign tumours in the uterus.
• in some cases, painful periods are hereditary. If a woman has painful periods, her daughters may later be affected in the same way.

Why do some women's periods stop altogether (amenorrhoea)?

Periods can stop for a number of reasons. The most common are:

• pregnancy.
• premature menopause (this can affect women in their early twenties).
• weight loss.
• weight gain.
• some forms of medication including the contraceptive pill or injections.
• drug abuse.
• stress.
• hormonal imbalances such as an underactive thyroid gland or the overproduction of a hormone called prolactin.
• a condition called polycystic ovaries (see below) is a very common cause of irregular or absent periods.

The treatment suggested will depend upon the diagnosis. If you are uncertain as to why your periods have stopped, seek advice from your doctor. Investigation usually involves a blood test to measure the levels of various hormones in your body.

Irregular, infrequent periods (oligomenorrhoea)

Periods are often light or infrequent both when a young woman starts having periods, and also when a woman is nearing menopause. This is normal because they are not producing an egg every month.

Many women experience one or two irregular periods every six months. This is not usually caused by any serious condition; however, many women do seek an explanation and reassurance from their GP or gynaecologist. The most common cause of infrequent periods is a condition called polycystic ovaries. This is a common condition affecting as many as ten per cent of women, in which a large number of very small (less than 1cm) cysts on the ovaries appear in association with a hormone imbalance. This condition results in irregular ovulation and thus periods are usually infrequent. The diagnosis of polycystic ovaries is made on the basis of one or more blood tests to measure hormones; a pelvic ultrasound scan of the ovaries is often taken as an additional test.

Treatment is only necessary if there is concern about the irregularity of periods or if a woman is having difficulty becoming pregnant.

Back