This is the normal physiologic process of monthly shedding of the lining of the uterus which develops every month in response to cyclic hormone changes associated with ovulation i.e. maturation and release of eggs.

Cause:
The ovary in all females at the time of birth contains all the eggs (approximately 2 million) she is supposed to have in her lifetime. The eggs remain dormant in ovaries till the age of puberty or sexual maturation. After this for almost 30 years, 8-10 eggs start maturing every month. Of these, only one matures and is released from the ovary. This whole cycle is under the control of centers in brain. These cyclic changes in hormones have effect on the whole body, especially breast and uterus. The lining of the uterus develops in response to the hormones released by the developing egg in anticipation of pregnancy. In the absence of pregnancy, the egg degenerates, hormone levels come down and the endometrim is shed in the form of menstruation.

Presentation:
A normal menstrual cycle comprises bleeding lasting from one to 5 days occurring at an interval of 28-30 days. There can be normal variation in interval, duration and amount of flow. Mild pain may be associated with perfectly normal cycle.

Symptoms of abnormal cycle:
Any change in cycle interval length, amount of bleeding or duration of bleeding is a sign of some problem in the menstrual cycle.

Management of normal menstruation:
Normal activity, including sports, studies, household work etc. can be continued during menses. There is no need for rest or restriction of activity. Personal hygiene is most important. Proper bathing and frequent changing of sanitary napkins is required.

Sex education:
At the beginning of menstruation the young girls need to be told about the following:

• Menstruation is a sign of sexual maturation.
• Guidance regarding personal hygiene.
• Remaining any unfounded fears and misconceptions.
• Risks of unsafe sexual behaviour.