PCOS is strongly correlated with obesity  I have PCOS. My mother has PCOS. I've been medicated for it since puberty. You know what it takes to get a PCOS diagnosis?  Doc: "How bad are your periods?"  Me: "Bad." Boom. PCOS. Seriously, lady doc took my blood pressure, height, and weight and that was it. I never even had an actual gyno exam (even though I had to see her once a year for a prescription) until about 5 years later because she said I had to once I hit 21. There is no blood tests, no hormone tests, nothing.  Obesity wreaks havoc on your hormones, which is exactly what PCOS does. The treatment is the same, a specific variety of hormonal birth control to regulate your body. Losing the weight only helps if you didn't have "real" PCOS to begin with or your obesity exacerbated your PCOS. Doctors aren't afraid to diagnosis PCOS at all because it's not a serious illness and the course of treatment is cheap and effective and highly unlikely to kill the patient or present any serious risks. Afterall diagnostic medicine exists to treat symptoms right?  You know how much weight I gained after both PCOS and hormonal birth control? 3lbs. And I was going through puberty so that may have just been my T&A coming in.