Difference Between Menstruation And Premenstrual syndrome
Menstruation is a woman’s monthly discharge of the inner lining of the uterus (endometrium). It lasts about 4 to 5 days and occurs, on the average, every 28 days. During the menstrual cycle, an egg (oocyte) matures and is released, a process called ovulation. At the same time, the uterus lining thickens to create a suitable environment in which a fertilized egg could develop into a fetus. If fertilization does not occur, this lining is shed, resulting in the menstrual period. Thus failure to menstruate can be the first indication of pregnancy.
Premenstrual syndrome (PMS) is a common name for a wide variety of recurring psychological and physical symptoms experienced by some women in the week or two before menstruation. Symptoms include sudden episodes of tearfulness, irritability, or depression; fatigue; water retention; headaches; and joint or muscle pain. Twenty to 50 percent of all women are believed to experience at least one symptom of PMS regularly; only 5 percent of these women are estimated to have symptoms severe enough to interfere with normal activity.
PMS can begin with puberty but is most common in women over age 25. The cause is still unknown, but one theory proposes that low progesterone levels in the second half of the menstrual cycle may be responsible. There is no cure for PMS, but oral contraceptive use or diet and exercise programs may alleviate some symptoms.