What is PCOS (Polycystic Ovary Syndrome)?

PCOS (polycystic ovary syndrome) is a very common condition in the UK, affecting approximately one in 10 women. Many women have PCOS but don’t know it, as it can be difficult to diagnose. In one study, up to 70 percent of women with PCOS hadn’t been diagnosed yet.

Update: in May 2026, PCOS was officially renamed PMOS (polyendocrine metabolic ovarian syndrome) to better reflect its hormonal and metabolic nature. The diagnostic criteria have not changed.

How is PCOS diagnosed?

For a PCOS diagnosis, you need to have 2 or more of the following:

1. Your period is irregular or infrequent. This indicates that the ovaries are not regularly releasing eggs (ovulating).
2. You have high levels of “male hormones” such as testosterone in your blood.
3. Your ultrasound scan shows you have polycystic ovaries (despite the name, these are actually not cysts). An ultrasound scan may not be required to confirm PCOS, since only two of these are needed for diagnosis.

1) Blood tests

Here are the labs you can ask your doctor about to check your PCOS, or to see if you might have PCOS:

Hormones (note: these fluctuate depending on where you are in your cycle):

• Full thyroid panel
• Total & free testosterone
• SHBG
• Progesterone
• LH, FSH, AMH
• DHEA-S, cortisol

Nutrient deficiencies:

• Vitamin D
• Vitamin B12 (especially important if you take metformin or oral contraceptives)
• Iron
• Magnesium, zinc

Insulin resistance:

• HbA1c
• Fasting insulin & 2-hour oral glucose tolerance test (OGTT). These should be done together and are the gold standard for assessing insulin resistance in PCOS.

Inflammation:

• hs C-reactive protein

2) Ultrasound

Ask for a pelvic ultrasound to check if you have lots of tiny, immature follicles on your ovaries.

3) Tracking your period

The average menstrual cycle is 28 days, but anything between 21 and 35 days is considered normal. Having fewer than eight cycles per year, or cycles lasting longer than 35 days, is considered irregular. Some women with PCOS have no periods for three or more cycles in a row. This is called amenorrhoea, and it’s the main cause of infertility in women with PCOS: if there are no periods, no eggs are being released. It’s helpful to track your cycle, so you always know how long it’s been since your last period.

If you notice a three-month break between periods, see your GP or a gynaecologist who can investigate the cause.

What are the symptoms of PCOS?

It can take over two years on average to be diagnosed with PCOS, because it looks different in everyone. You may experience several of the following symptoms:

• Irregular or absent periods
• Excess hair, particularly on the face, chest or stomach (hirsutism)
• Thinning of scalp hair
• Acne (especially on the back, chest and face)
• Difficulty maintaining a healthy body weight
• Fertility problems (difficulty getting pregnant)
• Patches of darker skin, especially in the folds of the neck, armpits, between the legs and under the breasts

Heart disease and diabetes are long-term health concerns associated with PCOS, particularly if you have any of the following:

• High levels of fats in the blood
• High blood pressure
• Extra weight, particularly around the middle

A combination of lifestyle changes and medication can help manage the symptoms of PCOS.

Can I have PCOS with no symptoms?

Yes, it is possible. People often don’t know they have PCOS until they have trouble getting pregnant or gain weight for no clear reason. There’s also the possibility of mild PCOS, where the symptoms aren’t noticeable.

Is there a cure for PCOS?

Although there is no cure for PCOS, it is possible to reduce the severity of the symptoms and prevent the complications associated with it, such as insulin resistance and diabetes.

Sources

1. BDA. 2019. Polycystic Ovary Syndrome (PCOS). Available at: bda.uk.com
2. “Polycystic Ovary Syndrome (PCOS): The Facts” by M. Elsheikh and C. Murphy (2008). ISBN 978-0-19-921368-9
3. March WA, Moore VM, Willson KJ, Phillips DI, Norman RJ, Davies MJ. The prevalence of polycystic ovary syndrome in a community sample assessed under contrasting diagnostic criteria. Hum Reprod. 2010;25(2):544-51.