What is menstruation?
At puberty, in girls the ovaries get enlarged and start producing eggs (ovum). One egg matures and is released by one of the ovaries once in about 28 to 30 days. During this period, the wall of the uterus becomes thick so as to receive the egg. If the egg is fertilised then it begins to develop and results in pregnancy. If this egg is not fertilised, the released egg and thickened lining of the uterus along with its blood vessels are shed off causing bleeding in female which is called menstruation. It occurs once in about 28 to 30 days.
