Different disorders which affect a woman's normal menstrual period are summarised under menstrual disorders. This includes excessively long and heavy bleeding (menorrhagia), abnormally heavy bleeding (hypermenorrhoea), abnormally light bleeding (hypomenorrhoea) and irregular or overly frequent bleeding (polymenorrhoea). If the menstrual period is associated with severe pain, this is known as dysmenorrhoea. Premenstrual syndrome is a clinical picture in its own right. This is explained in the premenstrual syndrome section.

A normal menstruation cycle lasts around 28 days. Individual deviations of two to three days can occur. Every cycle is concluded with bleeding, whereby the first day of the menstrual period is counted as the beginning of the new cycle. The menstrual period usually lasts for four to five days. Excessive deviations from the cycle duration, the bleeding duration and the extent of the bleeding are considered to be menstrual disorders.

An abnormally heavy menstrual period is when the blood loss per period is over 80 ml. High blood loss can either occur due to excessive bleeding during a menstrual period of normal length or during an overly long period lasting more than 7 days. In the first case, this is known as hypermenorrhoea; in the second as menorrhagia. Changes in the uterus such as myomas, endometriosis or infections are usually responsible for the excessive bleeding. Overly heavy bleeding can lead to a loss of iron or to anaemia. The treatment consists of eliminating the organic causes such as myomas or endometriosis. If there is no organic reason, hormone preparations can be used.

A very weak menstrual period is referred to as hypermenorrhoea. Hypermenorrhoea exists if the blood loss is less than 25 ml. The duration of the bleeding is often shortened to one or two days, or there is only weak spotting. Hypermenorrhoea occurs most frequently at the beginning of menopause.

If a menstrual period does not occur, this is known as amenorrhoea. Primary amenorrhoea is said to exist if the first menstrual period does not occur up to the age of 16. Causes can be hormonal disorders or malformations in the ovaries or the uterus. Secondary amenorrhoea exists if the menstrual period suddenly disappears in women who earlier had a normal menstrual cycle. Hormonal disorders, stress, extreme sporting stress, extreme fasting or eating disorders (anorexia) can cause secondary amenorrhoea.

Overly frequent menstrual periods are known as polymenorrhoea. According to the definition, polymenorrhoea exists if the menstrual cycle is shorter than 25 days. The cause is usually a disturbance in the feedback system between the brain and hormones which control the menstrual cycle. Hormone preparations can be used to treat and normalise the cycle.

A menstrual disorder which is characterised by excessive menstrual pain is known as dysmenorrhoea. Dysmenorrhoea causes colic-like lower abdominal pain during the menstrual cycle or severe back pain. Young women are often affected by it and no organic cause can be found. Between the ages of 30 and 40, excessively strong menstruation pain can occur due to changes in the uterus (myomas, endometriosis). If there are organic causes, the treatment focuses on eliminating the causes of the changes in the uterus.  If there is no organic cause, the focus is on treating the pain. Relaxation exercises and movement exercises can help to alleviate the pain.

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