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Polycystic ovary syndrome

Last updated: May 5, 2021

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Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hyperandrogenism, oligoovulation/anovulation, and/or the presence of polycystic ovaries. The diagnosis of PCOS is made following exclusion of disorders that may present with a similar clinical picture (e.g., congenital adrenal hyperplasia), most commonly by hormone analysis. Up to 50% of PCOS patients have metabolic syndrome, which is associated with obesity, insulin resistance, hypercholesterolemia, and an increased risk for endometrial cancer. PCOS primarily manifests with hirsutism, acne, and virilization. Diagnostic methods include a pelvic exam, blood tests for specific hormones, and ultrasound. Management consists of weight loss via lifestyle changes, and oral contraception pills are indicated in women who do not wish to conceive. The aim of treatment in women who desire to conceive is to normalize ovarian function and stimulate follicular growth (e.g., with clomiphene).

  • Prevalence: 6–12% of women in their reproductive years in the US [1]

Epidemiological data refers to the US, unless otherwise specified.

Hyperandrogenism in women is most commonly caused by PCOS.

Onset of symptoms typically occurs during adolescence.

Voice change may occur in severe forms of PCOS. However, it typically suggests a different underlying cause of hyperandrogenism.

Macroscopic appearance

  • Multiple, brown cysts arranged in a circular pattern in the subcapsular region of the ovary
  • Cysts are relatively small and of approximately the same size

Microscopic appearance

Hyperandrogenism [5]


  • Definition: A state of excess androgen levels that causes symptoms such as growth of facial hair, deepening of the voice, and male-pattern baldness.
  • For more information about physiological causes of hyperandrogenism, see “Pregnancy
Differential diagnosis of hyperandrogenism in females
Incidence Onset Characteristic finding
  • Most common (75–80% of cases)
  • Peripubertal
Nonclassic CAH
  • Common
  • Peripubertal
  • ↑ 17-Hydroxyprogesterone
  • Congenital
  • Ambiguous genitalia
Cushing disease
  • Any time
  • Any time
  • Uncommon
  • Any time
Androgen-secreting tumor (e.g., Sertoli-Leydig cell tumor, adrenal)
  • Primarily affects women 30–40 years of age
  • 3rd decade of life (mean age at diagnosis usually 40–45 years)
Ovarian hyperthecosis
  • Rare
Placental aromatase deficiency
  • Rare
  • Affected females: congenital
  • Maternal: during pregnancy
Drug-induced (e.g., exogenous steroid and androgen intake)
  • N/A
  • N/A

Clinical features


  • Laboratory tests to identify hyperandrogenemia
  • Investigate for the underlying cause


The differential diagnoses listed here are not exhaustive.

Rotterdam criteria

According to the American Association of Clinical Endocrinologists, at least two of three of the criteria below are required for diagnosis of PCOS after excluding other causes of irregular bleeding and elevated androgen levels.

Ovarian cysts are not required to diagnose PCOS.

Blood hormone levels

A clinical picture of hyperandrogenism fulfills a diagnostic criterion of PCOS, even in the absence of hormonal abnormalities.

Evaluate for metabolic disease

The therapeutic approach in PCOS is broadly based on whether the patient is seeking treatment for infertility.

General measures

  • Weight loss: if patient is overweight (BMI ≥ 25 kg/m2) in order to reduce estrone production by the adipose tissue
  • Lifestyle modifications
    • Exercise
    • Dietary changes (especially through caloric restriction)

Pharmacologic treatment

Infertility treatment

If treatment for infertility is not sought

If no treatment for infertility is sought, therapy should be aimed at controlling menstrual, metabolic, and hormonal irregularities.

Treatment of hirsutism

We list the most important complications. The selection is not exhaustive.

  1. PCOS (Polycystic Ovary Syndrome) and Diabetes. Updated: March 24, 2020. Accessed: April 30, 2020.
  2. American College of Obstetricians and Gynecologists' Committee on Practice Bulletins—Gynecology.. ACOG Practice Bulletin No. 194: Polycystic Ovary Syndrome.. Obstet Gynecol. 2018; 131 (6): p.e157-e171. doi: 10.1097/AOG.0000000000002656 . | Open in Read by QxMD
  3. Phiske M. An approach to acanthosis nigricans. Indian Dermatol Online J. 2014; 5 (3): p.239. doi: 10.4103/2229-5178.137765 . | Open in Read by QxMD
  4. Strain G, Zumoff B, Rosner W, Pi-Sunyer X. The relationship between serum levels of insulin and sex hormone-binding globulin in men: the effect of weight loss.. J Clin Endocrinol Metab. 1994; 79 (4): p.1173-6. doi: 10.1210/jcem.79.4.7962291 . | Open in Read by QxMD
  5. Screening and Management of the Hyperandrogenic Adolescent.
  6. Yin W, Falconer H, Yin L, Xu L, Ye W. Association Between Polycystic Ovary Syndrome and Cancer Risk. JAMA Oncology. 2019; 5 (1): p.106. doi: 10.1001/jamaoncol.2018.5188 . | Open in Read by QxMD