The most common hormonal abnormality in women is polycystic ovarian syndrome (PCOS). The etiology of the syndrome is not entirely clear. It is characterized by many immature preantral follicles in the ovaries and the thickening of the stroma which secretes excessive male hormones. It has been stated that the condition might be due to the wrong programming of hormones due to some factors in girls while still in the uterus of their mother. It is also stated that this condition may be triggered by wrong nutrition and excessive weight gain. It is most commonly seen in young girls and usually during puberty. Girls with PCOS are usually overweight, have hair loss, oily complexion and pimples. The syndrome is characterized by exacerbations and remissions. There is no treatment that can to cure the illness and thus treatment is instituted for alleviation of symptoms. Weight gain should be controlled and excessive weight should be lost through diet and exercise.

Weight gain and obesity in women could be divided into two. The first one is the apple or male type (central obesity) where weight gain is around the abdomen and the upper body and where the legs and thighs are thin. The second is pear type (peripheral obesity) where the upper body is thin and weight gain is around the thighs and legs. Cosmetically speaking apple type obesity is easier to conceal however health problems associated with it are worse than the pear type. Male type obesity is accompanied with high cholesterol levels. Weight gain in women with polycystic ovarian syndrome is apple type.

One of the findings in polycystic ovarian syndrome is dermatological changes such as hair loss, oily complexion and pimples. Anti-androgens (drugs to suppress male hormones) have to be used for their treatment.

Another finding in polycystic ovarian syndrome is irregular menstrual cycle due to the infrequency of absence of ovulation. Besides irregular menstrual cycles these women also have difficulty in conceiving. The menstrual cycle can be regulated using birth control pills in unmarried woman or women who do not want to have children. However, in women who want to get pregnant ovulation stimulating drugs must be used.

Especially in overweight women with PCOS there may be insulin resistance and hyperinsulinism. Insulin sensitizing medications (metformin) can be used to prevent long term consequences of hyperinsulinism.

In the long term, women with PCOS are under certain risks. One of these is the higher incidence of coronary diseases in these women when compared with the normal population due to high blood lipids. In addition, the incidence of breast cancers and cancer of the endometrium (inner lining of the uterus) is higher in these women. Furthermore, possibility of hypertension and surfacing of a latent diabetes during pregnancy is higher. There is also a higher risk of being diagnosed with diabetes after menopause in these women. Therefore, the long term effects of the disease should be considered. All these, can be minimised by controlling weight, weight loss, and correct nutritions.