Polycystic ovary syndrome (PCOS) is a common disease affecting 3-5% of women of reproductive age. Despite the fact that it was first recognised in 1935, the exact cause of the syndrome remains elusive and there is no ‘one-treatment-fits-all’ answer to its management.

The following pages cover this syndrome in some detail, with the final page containing information on support groups and the published references used to compile the information, with links to the original papers where available.

What symptoms does it cause?

The common symptoms of PCOS are as follows:

  • Period problems
  • Acne, excessively oily skin or hairiness (hirsutism) due to excess male-type hormones
  • Infertility
  • Weight gain


PCOS often comes to light during puberty due to period problems, which affects around 75% of those with the disease. Infrequent, irregular or absent periods are all common variations, many finding their periods particularly heavy when they do arrive. The period disturbance is a sign that there is a problem with regular monthly ovulation. Many teenagers use the contraceptive pill to control their periods as irregularity or heaviness is a common complaint at this time, even in the absence of PCOS. This often leads to a delay in the diagnosis of PCOS, many not presenting until the pill is stopped and finding periods cease or become irregular.


Androgens are a group of hormones, such as testosterone, found at high levels in men but present in women at much lower levels. PCOS sufferers often have higher than normal levels of androgens which most often causes excess hairiness, but some women find acne or even male-pattern hair loss a particular problem.


Given that the period disruption with PCOS is due to irregular or absent ovulation it is not surprising that it is a common cause of infertility. It is not usually 100% absolute, and some women with PCOS will ovulate normally, some will ovulate less frequently (leading to a delay to pregnancy) and some will not ovulate at all, meaning that for some treatment will definitely be necessary.


This is a double-edged sword for women with PCOS, around 40% of sufferers being overweight. Obesity itself will initiate the symptoms described above in some women who would not have otherwise suffered had they remained of normal weight. It will worsen the symptoms for those who do have PCOS and, unfortunately, the hormone changes associated with PCOS make weight loss more difficult.