Polycystic ovarian syndrome

Also known as:
Last Review Date: July 1, 2018

What is it?

Polycystic ovarian syndrome (PCOS), which was originally called Stein-Leventhal syndrome, is a common condition, affecting 5 to 10% of women of childbearing age. The disorder is probably the most common hormonal abnormality in women of reproductive age and one of the causes of infertility. It also seems to run in families. Although the underlying cause is not well understood, it is believed that an imbalance of sex hormones and resistance to the effects of the hormone insulin are the main problems. It is generally characterised by an excess production of androgens (male hormones - usually testosterone), anovulation (the egg is not released by the ovary) and menstrual disturbances, infertility and by a varying degree of insulin resistance.

Androgens are normally formed in small amounts by a woman's ovaries and adrenal glands. Even a slight overproduction can lead to symptoms such as hirsutism (increased body hair) and acne. In extreme cases, they can lead to virilisation (masculinisation).

Hormone imbalances also affect the menstrual cycle in PCOS, causing infertility problems. Most women with this condition do not have regular monthly periods. Often they have chronic anovulation and amenorrhoea, but they may also experience irregular periods and uterine bleeding. With PCOS, both ovaries tend to be enlarged as much as 3 times their normal size. In 90% of women with PCOS, an ultrasound of the ovaries will reveal cysts - small immature egg-bearing follicles, fluid-filled spaces - that can be seen on the surface of the ovary. These ovarian cysts are often lined up to form the appearance of a "pearl necklace." When the egg is not released and a woman is not menstruating, sufficient progesterone is not produced. This leads to a hormonal imbalance in which oestrogen goes "unopposed." This can lead to an overgrowth of the lining of the uterus (endometrial hyperplasia) and may increase a woman's risk of developing endometrial cancer. Women with PCOS who do ovulate and become pregnant tend to have an increased risk of miscarriage.

Although the cause of PCOS is not well understood, some think that insulin resistance may be a key factor. Insulin is vital for the transportation and storage of glucose at the cellular level; it helps regulate blood glucose levels and has a role in carbohydrate and lipid metabolism. When there is resistance to insulin's use at the cellular level, the body tries to compensate by making more. This leads to hyperinsulinaemia, elevated levels of insulin in the blood. Some believe that hyperinsulinaemia may be at least one cause for an increased production of androgens by the ovaries.

Most women with PCOS have varying degrees of insulin resistance, obesity, and blood lipid abnormalities. Insulin resistance tends to be more pronounced in those who are obese and do not ovulate. These conditions put those with PCOS at a higher risk of developing type 2 diabetes and cardiovascular disease.

Signs and symptoms

Polycystic ovarian syndrome is said to be heterogeneous; that is, patients may experience a wide variety of different symptoms to a greater or lesser degree, and vary over time. Also, a uniform and precise definition of the syndrome is lacking. Women often go to their doctor because they are having menstrual irregularities, experiencing infertility, and/or are having symptoms associated with androgen excess. They may experience:

  • Irregular menstrual periods or Amenorrhoea
  • Hirsutism involving male hair growth patterns such as hair on the face, sideburn area, chin, upper lip, lower abdominal midline, chest, areola, lower back, buttock, and inner thigh
  • Thinning hair, with male pattern baldness
  • Acne
  • Weight gain/obesity, with fat distribution around the centre of the body
  • Acanthosis nigricans
  • Skin tags in the armpits or neck


There is no specific test that can be used to diagnose polycystic ovary syndrome (PCOS) and there is no widespread agreement on what the diagnostic criteria should be. A health practitioner will typically evaluate a combination of clinical findings such as a woman's signs and symptoms, medical and family history, and physical exam as well as laboratory test results to help make a diagnosis.

Some testing may done to rule out other possible causes of PCOS-like symptoms before a PCOS diagnosis can be made. For example, adrenal or ovarian tumors or an overgrowth in adrenal tissue called adrenal hyperplasia can also cause an overproduction of male hormones in women.

Laboratory tests

  • FSH (follicle stimulating hormone), will be normal or low with PCOS
  • LH (luteinising hormone), will be elevated
  • Testosterone, total and/or free, usually elevated
  • Dehyrdoandroepiandrosterone sulphate (DHEAS) (may be done to rule out a virilising adrenal tumour in women with rapidly advancing hirsutism), frequently mildly elevated with PCOS
  • Oestradiol, may be normal or elevated
  • Sex hormone binding globulin (SHBG), may be reduced
  • Androstenedione, may be elevated
  • hCG (human chorionic gonadotropin), used to check for pregnancy, negative
  • Lipid profile (low HDL, high LDL and total cholesterol, elevated triglycerides)
  • Glucose, fasting and/or a glucose tolerance test, may be elevated
  • HbA1c to check for diabetes, may be elevated
  • TSH (thyroid stimulating hormone) to rule out hypothyroidism
  • AMH (anti mullerian hormone) is currently under investigation to help diagnose PCOS

Non-laboratory tests

Ultrasound, transvaginal and/or pelvic/abdominal are used to evaluate enlarged ovaries. With PCOS, the ovaries may be 1.5 to 3 times larger than normal and characteristically have more than 12 follicles per ovary, with each follicle less than 10 mm in diameter. Often the cysts are lined up on the surface of the ovaries, forming the appearance of a "pearl necklace." These ultrasound findings are not diagnostic.

Laparoscopy may be used to evaluate ovaries, evaluate the endometrial lining of the uterus, and sometimes used as part of surgical treatment.


There is no cure for polycystic ovarian syndrome. Although there have been cases involving the spontaneous resumption of menstruation, most women will have progressive symptoms until after menopause. Treatment of PCOS is aimed at reducing its symptoms and helping to prevent future complications. The goals are to promote ovulation, prevent endometrial hyperplasia, counterbalance the effects of androgen, and reduce insulin resistance. Treatment options depend on the type and severity of the individual patient's symptoms and on the patient's desire to become pregnant.

  • Diet, exercise, and maintaining a healthy body weight may help many women manage the symptoms of PCOS. These lifestyle changes are recommended to help decrease insulin resistance. Weight reduction can also decrease testosterone, insulin, and LH levels. Regular exercise and healthy foods will help lower blood pressure and cholesterol as well as improve sleep apnoea problems.
  • Drugs such as metformin may be prescribed to treat insulin resistance and diabetes. Metformin may also help to regulate menstrual periods and encourage ovulation.
  • Waxing, shaving, depilatory, and electrolysis or laser treatments may be used to remove excess facial and body hair.
  • Antibiotics or retinoic acids may be used to treat acne.
  • Oral contraceptives may be prescribed to help normalize menstrual periods.
  • Other medications may also be prescribe to stabilize hormone levels; treat more severe acne and/or excess hair; encourage or induce ovulation

Related pages

On this site
Tests: Insulin , FSH, LH, prolactin, testosterone, oestrogens, hCG, lipid profile, glucose, TSH, SHBG, HbA1c, DHEAS
Conditions: Infertility

Elsewhere on the web
Healthdirect Australia: polycystic ovarian syndrome
MedlinePlus: ovarian cysts
Jean Hailes for Women’s Health

J. M. Vink, S. Sadrzadeh, C. B. Lambalk, and D. I. Boomsma. Heritability of Polycystic Ovary Syndrome in a Dutch Twin-Family Study. The Journal of Clinical Endocrinology & Metabolism 91(6):2100 –2104.

doi: 10.1210/jc.2005-1494

M.P. Lauritsen, J.G. Bentzen, A. Pinborg, A. Loft, J.L. Forman, L.L. Thuesen, A. Cohen, D.M. Hougaard, and A. Nyboe Andersen. The prevalence of polycystic ovary syndrome in a normal population according to the Rotterdam criteria versus revised criteria including anti-Mullerian hormone. Human Reproduction, Vol.29, No.4 pp. 791–801, 2014.

Emily J. Fearnley, Louise Marquart, Amanda B. Spurdle, Philip Weinstein, Penelope M. Webb. The Australian Ovarian Cancer Study Group and The Australian National Endometrial Cancer Study Group. Polycystic ovary syndrome increases the risk of endometrial cancer in women aged less than 50 years: an Australian case–control study. Cancer Causes Control (2010) 21:2303–2308 DOI 10.1007/s10552-010-9658-7

Xin Li, Ruijin Shao. PCOS and obesity: insulin resistance might be a common etiology for the development of type I endometrial carcinoma. Am J Cancer Res 2014;4(1):73-79