What is PCOS? It seems to be in the news and on TV programs these days, but it is difficult to understand what it is, and what causes it. PCOS stands for "Polycystic Ovarian Syndrome," which is, at basis, a condition in which women produce many follicles on their ovaries each month, but generally do not produce a mature egg.

These follicles emit hormones, and wreak havoc on a woman's hormonal system. Since the follicles emit testosterone, they can cause a woman to grow facial hair. They also secrete insulin, which results in long-term insulin resistance, and can eventually result in full-blown Type II diabetes, which must be treated for the rest of a woman's life.

PCOS often is the cause for infertility. Many of us know that fertility requires a careful balance of female hormones in order to produce an egg on a regular basis. Since the woman suffering from PCOS has a deficit in estrogen and progesterone - the two primary female hormones associated with fertility and female qualities - she is often unable to produce an egg for fertilization.

What causes PCOS? It's been called a "syndrome" because the cause is unknown. Although we know that the follicles are overactive and unproductive, we don't know what causes this activity to take place.

We know that, in a normally functioning reproductive system, a woman's ovaries contain all the eggs she will have for her lifetime. These eggs are expressed from puberty to menopause, typically one per month. The mechanism of expression is the follicle, which both grows at the surface of the ovary and issues signaling hormones to let the rest of the body know when an egg is coming.

In a malfunctioning system, more than one follicle develops at a time. The excess of hormones may trigger a 'defensive' mechanism in the follicles which prevents their full expression, and thus inhibits overall production of an egg ready for fertilization.

The symptoms of PCOS can be confusing, as they are so diverse. The first indication is a weight gain, despite exercise and proper diet control. Insulin resistance occurs because of a spike in insulin production over a long period of time; the cells of the body receive an oversupply of insulin for so long that they develop an overall resistance, which results in insulin losing its effect to control serum glucose levels and results in a diabetes which needs to be controlled through diet, and sometimes through insulin injections.

Other symptoms can include acne (as a part of the hormonal storm), hair growth, and extremely irregular periods. A woman with PCOS can go for several months with no period, and then suddenly have extremely heavy bleeding for a longer-than-usual period of time.

Depression is a common symptom, which may be related to hormone-caused mood swings, or to other underlying causes of the disease. Of course, women who suffer these other symptoms, including infertility, would have reason to feel depressed.

Until recently, few physicians were trained to recognize PCOS. There are now a good deal more articles in the scientific literature on how both to recognize and treat the syndrome.