PCOS is a condition where at least two of the following, and often all three exists: 

At least 12 tiny cysts develop in your ovaries The balance of hormones made in the ovaries gets altered.In particular more male hormone than normal The follicles do not develop fully so the ovulation cycle changes and sometimes doesn't occur,you may not have a period. Its very common now a days due to current lifestyle. However, many of these women were healthy ovulated normally, and did not have high levels of male hormones.

Symptoms may include period problems, fertility problems,excess hair growth (Hirsutism), Acne, Thinning of scalp hair, weight gains, depression.

Long term problems causes increased risk of developing Type-2 diabetes,diabetes in pregnancy,high cholesterol and possibly high blood pressure.Full evaluation and assessment by means of BMI Blood tests-testosterone and LH ,USG Annual testing for diabetes or impaired glucose tolerance,cardiovascular risk factors such as blood pressure and blood cholesterol.

There is no cure for PCOS. Basically lifestyle modifications can be made to reduce health risks. Symptoms can be treated, weight loss, acne fertility issues and treating period problems, treating acne and preventing long term problems tackled selectively.