Dehydroepiandrosterone sulfate (DHEA-S) levels above 700–800 µg/dL are highly suggestive of adrenal dysfunction because DHEA-S is made exclusively by the adrenal glands. The free testosterone level is thought to be the best measure, with approximately 60 per cent of PCOS patients demonstrating supranormal levels.Some other blood tests are suggestive but not diagnostic. The ratio of LH (Luteinizing hormone) to FSH (Follicle-stimulating hormone), when measured in international units, is elevated in women with PCOS. Common cut-offs to designate abnormally high LH/FSH ratios are 2:1 or 3:1 as tested on Day 3 of the menstrual cycle. The pattern is not very sensitive; a ratio of 2:1 or higher was present in less than 50% of women with PCOS in one study. There are often low levels of sex hormone-binding globulin, in particular among obese or overweight women.Anti-Müllerian hormone (AMH) is increased in PCOS, and may become part of its diagnostic criteria. Glucose tolerance testing
2-hour oral glucose tolerance test (GTT) in women with risk factors (obesity, family history, history of gestational diabetes) may indicate impaired glucose tolerance (insulin resistance) in 15–33% of women with PCOS. Frank diabetes can be seen in 65–68% of women with this condition. Insulin resistance can be observed in both normal weight and overweight people, although it is more common in the latter (and in those matching the stricter NIH criteria for diagnosis); 50–80% of people with PCOS may have insulin resistance at some level. Fasting insulin level or GTT with insulin levels (also called IGTT).
The follicles have developed from primordial follicles, but this development has stopped ("arrested") at an early stage, due to the disturbed ovarian function. The follicles may be oriented along the ovarian periphery, appearing as a string of pearls on ultrasound examination.PCOS may be associated with chronic inflammation, with several investigators correlating inflammatory mediators with anovulation and other PCOS symptoms. Similarly, there seems to be a relation between PCOS and an increased level of oxidative stress. Diagnosis
Not every person with PCOS has polycystic ovaries (PCO), nor does everyone with ovarian cysts have PCOS; although a pelvic ultrasound is a major diagnostic tool, it is not the only one. The diagnosis is fairly straightforward using the Rotterdam criteria, even when the syndrome is associated with a wide range of symptoms. Differential diagnosis
Other causes of irregular or absent menstruation and hirsutism, such as hypothyroidism, congenital adrenal hyperplasia (21-hydroxylase deficiency), Cushings syndrome, hyperprolactinemia, androgen-secreting neoplasms, and other pituitary or adrenal disorders, should be investigated. Assessment and testing
Standard assessment
History-taking, specifically for menstrual pattern, obesity, hirsutism and acne. A clinical prediction rule found that these four questions can diagnose PCOS with a sensitivity of 77.1% (95% confidence interval [CI] 62.7%–88.0%) and a specificity of 93.8% (95% CI 82.8%–98.7%). Gynecologic ultrasonography, specifically looking for small ovarian follicles. These are believed to be the result of disturbed ovarian function with failed ovulation, reflected by the infrequent or absent menstruation that is typical of the condition.