What Causes Premenstrual Syndrome?

Even the experts don't really know what causes premenstrual syndrome (PMS) and why some women get it much worse than others. The working theory, however, is that PMS is due to a variety of factors including nutrition, genetics, psychological factors, and hormone changes.

The relationship of hormonal fluctuations to PMS is the factor that receives the most attention when it comes to scientific studies on the subject of PMS causes.

PMS comes just at the end of the menstrual cycle, from 7-14 days prior to menstruation. The purpose of the menstrual cycle, which averages around 28 days, is to cause an egg to mature and be released from an ovary for the purpose of fertilization (pregnancy). Hormones play a large role in these events, with the main players being estrogen and progesterone.

Embryo Nourishment

Some five days into the menstrual cycle, the ovaries will begin to give off the female hormone known as estrogen. Estrogen helps to thicken the uterine lining (endometrium) with a supply of nutrients for an embryo should conception occur. Some time around the 14th day of the menstrual cycle, ovulation occurs which is the release of the mature egg from the ovary.

Once ovulation occurs, the final phase of the menstrual cycle is begun: the luteal phase. This is the time that PMS symptoms occur. The ovaries are stepping up production of estrogen and progesterone to help ready the uterus for the possibility of pregnancy. If the egg fails to be fertilized, estrogen and progesterone levels will drop off. This drop in hormones triggers the death of the thickened uterine lining which is then shed via the vagina (menstruation). Once the blood flow begins, PMS symptoms dissipate and are gone either right away or within a day or so.

Brain Chemicals

Scientists think that there is an interaction between estrogen and progesterone with brain chemicals known as neurotransmitters. They believe that this interaction may be the culprit behind the emotional symptoms that are associated with PMS and may also contribute to the manifestation of physical PMS symptoms.

Other experts think that the reason only some woman will experience PMS symptoms while others do not may have a great deal to do with genetic factors. If your mother or sister had PMS, you have a higher risk for having PMS, too. This is true even though studies have yet to prove heredity as a causal factor for PMS.