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What is polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is the most common hormone condition to affect women of reproductive age. It is the main cause of irregular or absent periods. It can also cause acne and unwanted hair growth. In some, it causes scalp hair thinning

The ovaries are a pair of small organs that store eggs (each about the size of a walnut), located in the pelvis. Every month during the reproductive years, follicles, which contain developing eggs, start to grow and the largest will release a mature egg: this is called ovulation. If the egg is not fertilised, hormone levels fall and the next period starts two weeks after ovulation.

Polycystic ovaries contain an increased number of follicles, which can be seen on an ultrasound scan as tiny black holes. Polycystic ovaries are usually bigger than normal ovaries.

The ovaries of women with PCOS tend to produce more of the hormone called testosterone. They also tend to ovulate less frequently than typical ovaries.

What are the symptoms of PCOS?

Signs of PCOS usually develop in the late teens or early twenties. Some women have very mild symptoms, which may become a lot more noticeable if they gain weight, for example after having a baby.

The symptoms of PCOS are:

  • Irregular or absent periods
  • Unwanted hair growth, especially on the upper lip, chin, neck and lower tummy. It can also be found on the chest, around the nipples, back and/or bottom. These hairs are thicker and darker than those elsewhere on the body. Some may also have more and thicker, darker hairs on their arms and legs
  • Acne and greasy skin
  • Thinning scalp hair, especially on the top of the head

Women with PCOS tend to gain weight more easily and are often overweight as a result. While being overweight is not a symptom of PCOS, it does make the symptoms of PCOS worse.

If diagnosed with PCOS, you will need to be monitored for other conditions, such as type 2 diabetes and high cholesterol levels.

What causes PCOS?

While the exact cause of PCOS remains unknown, it is likely that genetics play a key role, which is why it often runs in families.

Women with PCOS are resistant to insulin, and their bodies produce more insulin to overcome this. Being overweight also drives insulin production. High levels of insulin make the ovaries produce more of the hormone testosterone, which can lead to acne or unwanted hair growth. In addition, insulin can interfere with the normal growth of follicles, impacting the frequency of ovulation.

When should I consult a GP?

Talk to your doctor if you think you have PCOS. The doctor will ask about symptoms and take your blood pressure. They may arrange a hormone blood test and a pelvic ultrasound scan to exclude other causes of your symptoms.

It can be normal for women to have polycystic ovaries, and approximately one in five women will have these on an ultrasound scan but have regular periods and no symptoms. This does not mean they have polycystic ovary syndrome (PCOS).

Only women who have symptoms have PCOS and most of these women will have PCO on an ultrasound scan. Approximately 8% of women have PCOS.

What treatments are available?

There's no cure for PCOS, but the symptoms can be treated.

Trying to control your insulin levels by what you eat does not influence the symptoms of PCOS, but losing some weight, eating better and being more active improves most of the symptoms.

There is medication for unwanted hair growth, acne, irregular periods and to help with getting pregnant. Laser and electrolysis can also be effective for unwanted hair growth, especially in combination with hormone treatment. There is a non-hormonal cream available that blocks the enzyme that makes hair, which some find helpful.

What are the consequences of PCOS?

If periods are irregular or absent, this means that ovulation is less frequent than normal, or might not be happening. This can cause a delay in getting pregnant.

Very heavy or very light periods can be caused by PCOS as a result of infrequent ovulations.

Diabetes is more common, especially in those who are overweight and/or have a family history of type 2 diabetes. Diabetes in pregnancy (called gestational diabetes) is also more common.

PCOS may also be associated with increased cholesterol and raised blood pressure, and these findings are more likely in those who are overweight.

If periods are very infrequent, especially if less than four times a year, the lining of the womb can become too thick, which increases the risk of developing into endometrial cancer.

Will I be able to have a baby?

Women with PCOS who have regular menstrual cycles are likely to have the same chance of having a baby as anyone else.

Those with infrequent or no periods can usually be helped by a fertility treatment called ovulation induction, which can be given as tablets or injections. This is a very successful treatment and the chance of having a baby is about the same as for women who have naturally regular periods. However, it does not work very well for those who are overweight and therefore weight loss is a very important part of fertility treatment for those with PCOS.

Some women will be offered a surgical procedure called laparoscopic ovarian drilling to help them ovulate, which is done under a general anaesthetic.

Find more information about PCOS symptoms, diagnosis and treatment, please visit:

The NHS website
The Royal College of Obstetricians and Gynaecologists

Verity PCOS
AskPCOS – available for android and iPhones