However, there is a viable theory that may explain why PMS occurs. Hormone changes occur regularly in women of all ages. Women who have normal cycles tend to have higher estrogen levels at the start of a period and lower levels at the end of the cycle. PMS occurs before the menstrual cycle and generally subsides once menstruation begins. Some of the more common symptoms can include mood swings, breast tenderness, cramps, headaches, cravings, depression, changes in bowel habits, fatigue, blemishes, weight gain and so on.
Severity varies from women to women, but seems to increase with age.
Stress may also be a factor. Most women get by without needing medical assistance. However, there is a small percentage that do require it. PMS most often affects women who have undergone major hormonal changes in life. Example of this would be, childbirth, miscarriage, abortion, stopping birth control pills, and amenorrhea.