Common signs and symptoms of PCOS include the following:

Menstrual disorders: PCOS mostly produces oligomenorrhea (fewer than nine menstrual periods in a year) or amenorrhea (no menstrual periods for three or more consecutive months), but other types of menstrual disorders may also occur. Infertility: This generally results directly from chronic anovulation (lack of ovulation). High levels of masculinizing hormones: Known as hyperandrogenism, the most common signs are acne and hirsutism (male pattern of hair growth, such as on the chin or chest), but it may produce hypermenorrhea (heavy and prolonged menstrual periods), androgenic alopecia (increased hair thinning or diffuse hair loss), or other symptoms. Approximately three-quarters of women with PCOS (by the diagnostic criteria of NIH/NICHD 1990) have evidence of hyperandrogenemia. Metabolic syndrome: This appears as a tendency towards central obesity and other symptoms associated with insulin resistance, including low energy levels and food cravings. Serum insulin, insulin resistance, and homocysteine levels are higher in women with PCOS. Polycystic Ovaries: Ovaries might get enlarged and comprise follicles surrounding the eggs. As result, ovaries might fail to function regularly.Women with PCOS tend to have central obesity, but studies are conflicting as to whether visceral and subcutaneous abdominal fat is increased, unchanged, or decreased in women with PCOS relative to reproductively normal women with the same body mass index.
Drug tolerance or drug insensitivity is a pharmacological concept describing subjects reduced reaction to a drug following its repeated use. Increasing its dosage may re-amplify the drugs effects; however, this may accelerate tolerance, further reducing the drugs effects. Drug tolerance is indicative of drug use but is not necessarily associated with drug dependence or addiction. The process of tolerance development is reversible (e.g., through a drug holiday) and can involve both physiological factors and psychological factors.One may also develop drug tolerance to side effects, in which case tolerance is a desirable characteristic. A medical intervention that has an objective to increase tolerance (e.g., allergen immunotherapy, in which one is exposed to larger and larger amounts of allergen to decrease ones allergic reactions) is called drug desensitization.The opposite concept to drug tolerance is drug reverse tolerance (or drug sensitization), in which case the subjects reaction or effect will increase following its repeated use. The two notions are not incompatible and tolerance may sometimes lead to reverse tolerance. For example, heavy drinkers initially develop tolerance to alcohol (requiring them to drink larger amounts to achieve a similar effect) but excessive drinking can cause liver damage, which then puts them at risk of intoxication when drinking even very small amounts of alcohol.Drug tolerance should not be confused with drug tolerability, which refers to the degree to which overt adverse effects of a drug can be tolerated by a patient.