Polycystic Ovarian Syndrome or PCOS is a complex disorder that affects almost 6-20% of reproductive age women, worldwide (depending upon the diagnostic criterion).  Being heterogenous and multi-faceted in nature, PCOS shows up in different women in different ways, making it hard to diagnose correctly. Common symptoms include acne, irregular periods, increased facial hair growth, hair thinning, skin tags, dark skin folds (Acanthosis nigricans), mood swings and depression. PCOS has also been associated with weight gain and obesity in many women, although it is not a necessary condition. In reality, diagnosing PCOS is complicated and protocols can differ from doctor to doctor.
The mostly widely accepted standard for diagnosing PCOS is known as the Rotterdam Criteria. Per this standard, someone must exhibit at least two of the three following symptoms, in order to be clinically diagnosed with PCOS:
To test for the above three conditions of the Rotterdam criteria, medical practitioners usually rely on a combination of lab work and input from the patient.
Androgen excess or hyperandrogenism can be determined chemically via a blood test (to check for elevated serum levels of total, bioavailable, or free testosterone or dehydroepiandrosterone sulfate ) or clinically by paying attention to any visible manifestations such as hirsutism and acne. Hirsutism refers to the unwanted male-pattern hair growth especially on the upper lip and on the chin, back and chest. Thinning of hair on the head (male-pattern baldness) can also be a sign of hyperandrogenism.
A polycystic ovary is ascertained via an ultrasonography and either (1) contains 12 or greater follicles measuring 2-9 mm in diameters (or 25 or more follicles using new ultrasound technology) or (2) has a volume of greater than 10 mL. A single ovary meeting one or both the definitions is enough for a diagnosis of polycystic ovaries. However, many doctors do not prescribe a USG unless the patient has only met one of the other Rotterdam criteria. 
Irregular periods or infrequent periods are usually diagnosed with the input of the patient and consideration of past menstrual history. Doctors typically wait for 2 years after the patient first starts menstruating to evaluate whether the menstrual cycle is regular or not. It is also important to note, that periods lengths can look vary for individuals, and attention needs to be paid to sudden deviations.
Misdiagnosis of PCOS
Some medical practitioners like to rule out other conditions such as pregnancy, thyroid dysfunction, hyperprolactinemia, and nonclassical congenital adrenal hyperplasia  before settling upon PCOS. This is important because PCOS is associated with such a wide variety of symptoms and can be easily misdiagnosed. Irregular periods, for instance, can also be attributed to both pituitary amenorrohea and thyroid problems. Lab work can be helpful in narrowing down potential causes. Family history and genetics are also taken into account when evaluating symptoms such as facial hair growth and other signs of androgen excess.
Despite being a common condition in women’s health, 7 out of 10 women with PCOS go undiagnosed. This can happen for a few reasons: symptoms can be mild, there isn't enough awareness about this condition, and there isn't equal access to good quality healthcare. Many women only realise they have PCOS when they experience issues around conception and visit a doctor to investigate.
Diagnosing PCOS, however, is important for long-term metabolic and cardiovascular health. As a chronic condition, PCOS cannot ever be fully cured, but its symptoms can be regulated with the right interventions. In many cases, if PCOS remains undiagnosed and unmanaged, it can lead to several health complications such as cardiovascular diseases, infertility, sleep apnea, type 2 diabetes and depression.
According to the CDC, 50% of women with PCOS develop Type 2 Diabetes by the age of 40
If you identify with the symptoms discussed above (increased facial hair, male pattern baldness or absentee periods), then it may be time for a conversation with your physician. Given that PCOS is associated with a wide range of symptoms affecting different parts of the body, some women consult multiple specialists - endocrinologists, ob/gyns, therapists, dermatologists and nutritionists - to form treatment plans. This process can be overwhelming and confusing, so we highly recommend finding a support system in other women who are navigating PCOS.