Polycystic ovary syndrome (PCOS)

About polycystic ovary syndrome

Women have two ovaries, which are small organs inside your body where eggs (ova) mature and are then released. This happens about once a month. The ovaries produce the hormones oestrogen, progesterone and testosterone.

Polycystic means 'many cysts'. Cysts are fluid-filled sacs. Before ovulation, the egg develops in a small swelling on the ovary called a follicle. Cysts form when follicles stop growing too early. Instead of bursting to release the egg, they form swollen egg chambers (cysts). A polycystic ovary generally has 12 or more cysts. These cysts are usually benign, which means they aren’t cancerous.

If you have PCOS, you will usually have two of the following.

  • High levels of the male hormone testosterone, which is produced by your ovaries, and/or signs of having high levels of testosterone (such as excess body hair or thinning of the hair on your head).
  • Irregular or no release of eggs from your ovaries (ovulation), which usually means you have irregular or no periods.
  • Many small cysts on your ovaries called polycystic ovaries.

In the UK, it's estimated that between five and 10 in every 100 women may have PCOS. It can affect your hormone levels, periods (menstrual cycle), fertility, appearance and long-term health.

Symptoms of polycystic ovary syndrome

If you have PCOS, you may start to notice symptoms in your late teens or 20s, such as:

  • absent or irregular periods
  • infertility (you need to ovulate to become pregnant and may not be ovulating regularly or at all)
  • being overweight
  • excess hair (hirsutism) on your face, around your nipples or on your lower abdomen (tummy)
  • thinning of the hair on top of your head
  • oily skin
  • acne

Complications of polycystic ovary syndrome

If you have PCOS, you may have a higher risk of developing diabetes and heart disease later in life. If you have less than three periods in a year, you might also be at higher risk of womb cancer.

It’s important to have regular health checks with your GP.

Causes of polycystic ovary syndrome

The exact reasons why you may develop PCOS aren't fully understood at present. Several factors seem to be important.

  • PCOS runs in some families, so there may be a genetic link.
  • High levels of certain hormones may also cause PCOS. For example, you may have resistance to insulin, the hormone that controls your blood sugar level. This means the level of insulin in your blood needs to be higher than normal to control your blood sugar level. The extra insulin may cause your ovaries to make too much testosterone, which can lead to excess hair and acne. Increase in testosterone can also stop ovulation.
  • If you have excess body fat, this can make both insulin resistance and the symptoms of PCOS worse.

Diagnosis of polycystic ovary syndrome

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.

Your doctor will look for any signs of PCOS and rule out other problems that cause similar symptoms. Common tests include:

  • blood tests – to check how well your thyroid is working, and measure your level of glucose and hormones such as testosterone
  • an ultrasound scan – to see if your ovaries are enlarged and/or polycystic

After the tests above, if your GP thinks you may have severe PCOS or problems with infertility, he or she may refer you to a specialist doctor such as a gynaecologist – a doctor who specialises in women's reproductive health.

Having cysts on your ovaries doesn't necessarily mean you have PCOS. It's also possible that you will be diagnosed with PCOS even if you don't have any cysts on your ovaries.

Treatment of polycystic ovary syndrome

There isn’t a cure for PCOS – your treatments aim to control symptoms of the condition. For some women their symptoms go away without any treatment but for most women, their symptoms get worse until they reach the menopause.

Self-help treatments

Your GP or gynaecologist is likely to suggest that you make some lifestyle changes, such as eating a healthy, balanced diet and exercising regularly, to help control your symptoms, reduce insulin resistance and improve your fertility.

Stress can make your symptoms worse so managing your stress levels and finding time to relax can also help control your symptoms.

If you have excess hair, you can control this with hair removing creams or by bleaching, shaving or waxing. Laser treatment and electrolysis can give longer-lasting results – see a qualified professional for these procedures.


A number of medicines are available that can help treat the different symptoms of PCOS, which include the following.

  • Over-the-counter treatments that contain benzoyl peroxide (eg PanOxyl) can help reduce acne. If over-the-counter treatments don't help, speak to your doctor. He or she may prescribe antibiotic tablets or creams to treat your acne.
  • Oral contraceptives (eg Dianette) can stop your ovaries from producing too much testosterone, so improve both acne and excess hair.
  • Metformin is a medicine that increases the sensitivity of muscle cells to insulin (reduces insulin resistance). This means your body needs less insulin to control your blood sugar levels. Reduced insulin levels in the blood means your ovaries will produce less testosterone. As the testosterone levels drop, symptoms such as excess hair and irregular periods will improve and your ovaries will start to release eggs and your fertility will improve.
  • Fertility medicines including clomifene citrate and tamoxifen can stimulate your ovaries to release eggs. You can take these for up to a year. If clomifene citrate makes you ovulate but you don't become pregnant after six months, your doctor might suggest intrauterine insemination (this is when sperm is placed directly into your womb). If fertility medicines don't help improve your fertility, your doctor may offer hormone therapy or surgical treatment. You can also consider assisted conception, such as IVF (in vitro fertilisation), egg donation or surrogacy.

Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.


If medicines, such as clomiphene citrate, haven’t worked for you, your doctor may suggest surgery to control PCOS symptoms and improve your fertility, for example laparoscopic ovarian drilling. This is a type of keyhole procedure that destroys the tissue on your ovaries that produces testosterone. As levels of testosterone fall, your PCOS symptoms should improve and your ovaries should start to release eggs again.

Does having polycystic ovary syndrome increase the risk of complications during fertility treatment?


Yes, having polycystic ovary syndrome (PCOS) does increase your risk of having certain complications when you’re on fertility treatment.


If you have fertility treatment to stimulate the development of eggs in your ovaries, this can sometimes lead to a condition called ovarian hyperstimulation syndrome (OHSS). OHSS occurs when the fertility medicines you're taking cause an excessive response from your ovaries. If you have PCOS, your risk of getting OHSS is increased.

This risk of developing OHSS is lower if you're taking the fertility medicine clomifene citrate than if you have hormone therapy. You can have this alone or in combination with more complex fertility treatment such as IVF (in vitro fertilisation).

OHSS causes your ovaries to become enlarged. Symptoms of OHSS include:

  • abdominal (tummy) swelling or bloating
  • abdominal pain
  • feeling sick
  • vomiting
  • shortness of breath

See your gynaecologist if you have any of these symptoms.

Will having polycystic ovary syndrome affect me or my baby if I get pregnant?


Yes, you're more likely to have complications during your pregnancy if you have PCOS.


If you have PCOS, you may develop diabetes during your pregnancy, especially if you're very overweight. This is called gestational diabetes. Your GP will test you for it early in your pregnancy. If you do get diabetes while you're pregnant, your GP or midwife will refer you to a diabetes clinic. Gestational diabetes usually goes away once your baby is born, but you may be more likely to develop diabetes later in life.

If you have PCOS, you’re more at risk of having high blood pressure in pregnancy, pre-eclampsia, and having a premature baby. High blood pressure affects how your kidneys work. A sign of poor kidney function is the presence of protein in your urine (the kidneys stop filtering the blood properly so proteins leak into your urine).

In pregnancy, high blood pressure and the presence of protein in your urine is known as having pre-eclampsia. Pre-eclampsia can affect the development of your placenta and your baby's growth. Severe pre-eclampsia (very high blood pressure) is a serious condition that can potentially harm you and your baby. Symptoms of pre-eclampsia include:

  • headaches
  • blurred or altered vision
  • vomiting
  • abdominal pain
  • shortness of breath
  • swelling of your face, hands or feet

If you have any of these symptoms, seek urgent medical attention. If you have pre-eclampsia, you may need to be monitored in hospital in case you need treatment or your baby needs to be delivered early.

Will the symptoms of polycystic ovary syndrome improve if I lose weight?


Yes. If you're overweight, losing weight often helps to improve the symptoms of PCOS.


One of the causes of PCOS is insulin resistance. If you're obese, this increases your insulin resistance and may make your symptoms worse. Exercising and eating healthily can help you to lose weight and become more sensitive to insulin. Aim to do 30 minutes of vigorous exercise every day.

If your periods are irregular, you may find that losing weight makes them more regular. If you aren't having periods, losing weight may lower your insulin levels enough so that you start ovulating. Weight loss may also help to reduce excess hair growth and lower the risk of your womb lining thickening.

Eating a healthy, balanced diet, doing regular exercise and losing excess weight will also reduce your risk of getting type 2 diabetes and heart disease, which women with PCOS have a higher risk of developing.

Can polycystic ovary syndrome be cured?


No, PCOS can't be cured. However, there are effective treatments for some of the symptoms.


Many of the symptoms of PCOS can be treated but the condition itself is unlikely to go away. Your treatment will depend on the type and severity of your symptoms, your age, and whether or not you wish to get pregnant.

There is a variety of treatments for PCOS. These include:

  • improving your lifestyle
  • medicines
  • fertility treatments

Ask your GP for advice on which treatments are suitable for you.

If you have your ovaries removed, can you still get polycystic ovary syndrome?


Yes, even if you have your ovaries removed, you can still get PCOS. This is because the condition also involves other organs and tissues, such as your adrenal glands and pancreas.


There isn’t a cure for PCOS at present. Even if you have your ovaries removed in an operation called an oophorectomy, the condition won’t go away.

The exact reasons why you may develop PCOS aren't fully understood at present. However, it’s thought that insulin resistance plays a major role. Insulin is a hormone that regulates the level of glucose in your blood. Glucose is a simple form of sugar that's absorbed by your body as a natural part of digestion and is carried around your body in your blood. When glucose reaches your body tissues, such as muscle cells, it's absorbed and converted into energy.

Insulin is secreted into your blood by your pancreas, which is a gland located behind your stomach. If you have insulin resistance, your body's cells stop responding to the hormone. Your body then senses that glucose is low in your cells and sends a signal to your pancreas to release more insulin. These elevated levels of insulin can affect the balance of your sex hormones. Your ovaries, for example, can produce higher levels of the male hormones testosterone and androstenedione, which can cause the PCOS symptoms of hair growth and acne.

Therefore, PCOS isn’t just affected by your ovaries. If you have surgery to remove your ovaries, it won’t address the underlying insulin resistance which has contributed to the sex hormone imbalance in the first place. It may possibly improve your symptoms but it won’t cure the condition. Furthermore, testosterone is produced in both your ovaries and your adrenal glands (at the top of your kidneys) so removing your ovaries won’t stop your body making this sex hormone.

There are medicines available that can reduce your symptoms. However, if medicines don’t work for you, your doctor may suggest laparoscopic ovarian drilling surgery to control PCOS symptoms and improve your fertility. This is a type of keyhole procedure that destroys the tissue on your ovaries that produces testosterone but leaves your ovaries intact.

Ask your GP or gynaecologist for more information on appropriate treatments for you.