Dysmenorrhoea

Up to three-quarters of women have period pain, also known as dysmenorrhoea, at some time. In about a fifth of these women, the pain is severe and can seriously disrupt normal activities. Pain is usually experienced in the 24 hours before menstruation or over the first 1 or 2 days of the period.


What are the types?

There are two types of dysmenorrhoea; primary, which has no obvious cause; and secondary, which is the result of a disorder of the reproductive organs.

Primary dysmenorrhoea. This form of dysmenorrhoea usually appears in the early teens and is associated with the hormones involved in the monthly release of eggs from the ovaries. Periods often become painful about 1 -2 years after the start of menstruation, when ovulation begins. A rise in the level of hormone-like substances called prostaglandins in the body occurs some days after ovulation and makes the muscles of the uterus contract. This contraction interferes with the blood supply to the uterus and causes period pain. This type of menstrual pain tends to lessen after the age of 25, often disappearing by the age of 30, and it usually becomes less severe after childbirth, probably because the blood supply to the uterus increases.

Women with close female relatives who have had primary dysmenorrhoea are more likely to develop it, suggesting that genetic factors are involved.

Secondary dysmenorrhoea. Painful periods in women who have not experienced menstrual pain before or have only had mild pain is called secondary dysmenorrhoea. This type of period pain usually affects women between the ages of 20 and 40. The cause is often endometriosis, in which fragments of the tissue that normally lines the uterus become attached to other organs in the pelvis, or a disorder of the uterus, such as a fibroids. A persistent infection of the reproductive organs and use of an intra-uterine contraceptive device (IUD) may also cause painful periods.

What are the symptoms?

The symptoms of dysmenorrhoea begin either just before or at the start of menstruation and are worst when bleeding is heaviest. The pain may be described as either or both of the following:

- Cramping lower abdominal pain that comes in waves, radiating to the lower back and down the legs.
- Dragging pain in the pelvis.

This pain may be accompanied by any of the symptoms of premenstrual syndrome (right), such as headache.

What can I do?

Taking certain over-the-counter painkillers, such as ibuprofen, may help to alleviate the discomfort. Relaxing in a hot bath and applying a source of heat, such as a hot-water bottle, to your abdomen may also provide pain relief. However, consult your doctor if you are experiencing period pain for the first time or if the pain becomes severe.

What might the doctor do?

Your doctor will probably examine you, especially if you have secondary dysmenorrhoea. Various tests may be carried out, including a cervical swab to look for infection, ultrasound scanning of the lower abdomen, or examination of the uterus with an instrument called a hysteroscope.

Treatment depends on the type of dysmenorroea. If you have primary dysmenorrhoea, your doctor may prescribe a nonsteroidal anti-inflammatory drug or an anti-spasmodic drug to reduce cramping pain. In some cases, your doctor may prescribe oral contraceptive pills, which relieve period pain by preventing ovulation and can also decrease menstrual blood loss. Once ovulation has been suppressed, primary dysmenorrhoea should improve, but the pain may recur at any time if you stop treatment. Secondary dysmenorrhoea usually disappears once the underlying condition is treated.