Polycystic ovary syndrome

In polycystic ovary syndrome (PCOS), the balance of male and female hormones that regulate the production and release of eggs is disrupted.

This causes one or more of the following:

• Eggs don't develop properly or aren't released from your ovaries
• Excess male hormones (androgens)
• Enlarged follicles (polycystic ovaries) — follicles are fluid-filled sacs in your ovaries where eggs develop 

The enlarged fluid-filled sacs prevent eggs from being released and give the condition its name. However, the term polycystic can be confusing, as you don’t actually have cysts if you have PCOS.

Symptoms include irregular periods, acne and excess facial or body hair (as a result of male hormones). PCOS often leads to infertility.

Roughly one in five women in the UK are thought to have PCOS, although more than half don’t have symptoms. It usually starts in the teenage years.

Although there's no cure, PCOS can be effectively treated and symptoms managed.

Ovaries contain fluid-filled sacs called follicles. As they develop, they grow in size and can each potentially release an egg — this occurs at ovulation. Polycystic ovaries contain more of these follicles, each up to 8mm in size. However, they fail to mature and can’t release an egg.

It’s difficult to know exactly how many women have PCOS, but it’s thought to be very common.

PCOS symptoms usually start in your teenage years or early twenties. Common symptoms include: 

• Acne
• Difficulty getting pregnant
• Excess facial or body hair (hirsutism)
• No periods or irregular, prolonged or heavy periods
• Thinning hair
• Weight gain

You may not experience all of these symptoms and each symptom can range from mild to severe. You may only experience period problems and/or difficulty getting pregnant. Your symptoms may also change over time, eg acne in your early twenties may become less of a problem in your forties but excess hair may become more of a problem.  

In later life, PCOS is also linked to an increased risk of developing high cholesterol and type 2 diabetes.

Many women are only diagnosed with PCOS when they find it difficult to get pregnant. PCOS is one of the most common causes of infertility in women. 

PCOS can cause irregular periods or no periods at all. This is because the ovaries fail to release eggs (ovulation) or do so infrequently, which causes infertility. 

PCOS can increase your risk of certain health problems in later life, including: 

• Cancer of the womb lining (endometrial cancer) — this type of cancer is higher in women who have no periods at all or fewer than three or four a year; the overall risk is still small and can be reduced with treatments to regulate your periods, such as the contraceptive pill or intrauterine system (IUS)
• Depression, mood swings and self-esteem issues
• High blood pressure and high cholesterol  — this can lead to heart disease and stroke
• Sleep apnoea — this causes your breathing to be interrupted while you sleep
• Type 2 diabetes — this causes levels of sugar in your blood to become too high

If you’re experiencing symptoms of PCOS (see above), see your GP. Your GP will ask about your symptoms and check your blood pressure. They may also arrange further investigations, including:  

• An ultrasound scan to see whether you have a high number of follicles in your ovaries
• Cholesterol test
• Diabetes screening 
• Hormone tests to determine whether excess hormone production is caused by PCOS or another condition

They may recommend that you are regularly screened for diabetes. How often you are screened will depend on your age, weight and other factors. If you are aged 40 or over, diabetes screening is usually recommended every three years. 

After your GP has ruled out other causes of your symptoms, a diagnosis of PCOS can usually be made if you meet at least two of the following criteria: 

• High levels of male hormones — this is detected using a blood test
• Irregular or infrequent periods
• Polycystic ovaries — this is detected by an ultrasound scan

An ultrasound scan is not always needed to be given a diagnosis of PCOS.

You can be treated for PCOS by your GP or your GP may refer you to a specialist — a gynaecologist or an endocrinologist. Your doctor will discuss how to manage your symptoms, including recommended lifestyle changes, and will prescribe you medication.

The exact cause of PCOS is unknown but abnormal hormone levels are thought to be involved.

Some women with PCOS have insulin resistance, the hormone that helps control blood sugar levels. This causes your body to produce more insulin to compensate, which can trigger the ovaries to increase the production of male hormones, such as testosterone. Being overweight or obese also causes your body to produce more insulin. 

It’s normal for women to have low levels of male hormones. However, if you have too much, you may have problems with ovulation and excess facial and body hair.

PCOS often runs in families, suggesting that specific genes are linked to the condition.

Insulin is a hormone that your body produces to control sugar levels in your blood. It helps glucose, a type of sugar, move from your blood into your cells where it is used for energy. 

Insulin resistance makes your body less responsive to insulin. Consequently, your body makes even more insulin to elicit a response.

Insulin resistance can also cause weight gain. Excess fat causes your body to make more insulin. 

The resulting high insulin levels caused by insulin resistance make your ovaries produce too much of the male hormone testosterone. This worsens symptoms of PCOS and disturbs the development of follicles in your ovaries, which interferes with ovulation.

In many cases of PCOS, women have abnormal hormone levels, such as: 

• Higher LH (luteinising hormone) levels — this hormone stimulates ovulation but too much may have a negative impact on the ovaries
• Higher prolactin levels — this hormone stimulates glands in your breasts to make milk during pregnancy 
• Higher testosterone levels — all women have low levels of this male hormone but it is often raised in PCOS
• Lower SHBG (sex hormone-binding globulin) levels — this protein is found in your blood and binds to testosterone to reduce its effects

It isn't yet known what causes these hormonal changes. It may be due to a problem with your ovaries, other glands that make hormones, or a part of your brain that regulates the production of these hormones. Insulin resistance also causes hormonal imbalances. 

PCOS can run in families. If your aunt, mother or sister has PCOS, you're more likely to develop it. This suggests there may be genetic risk factors for PCOS but the specific genes involved haven't been identified yet. 

There's no cure but you can treat the symptoms. PCOS treatments include:

• Fertility treatments
• Lifestyle changes, such as diet and weight loss
• Medications to balance hormones and reduce hair growth

If fertility treatments are unsuccessful, your doctor may recommend a simple surgical procedure called laparoscopic ovarian drilling (LOD), which is carried out under general anaesthetic. A thin, tube-like telescope is passed through a small cut made in your abdomen and then a laser or heat is used to destroy the tissue in your ovary that is producing excess male hormones. This helps restore a normal balance of hormones so your ovaries can function correctly.

If you have PCOS and are overweight, you can reduce your symptoms and your risk of developing health problems in later life by losing extra weight — losing as little as 5% of your total body weight can make a difference. 

To find out if you are overweight, calculate your BMI (body mass index). A healthy BMI range is 18.5–24.9.

To lose weight, exercise regularly and eat a healthy, balanced diet, including: 

• At least five portions a day of fruit and vegetables
• Chicken, fish and lean meats
• Whole foods such as wholegrain cereals and wholemeal bread

If you need dietary advice, see your GP — they may refer you to a dietitian.

Medications can treat the different symptoms of PCOS.

Absent or irregular periods can be treated with: 

• Contraceptive pill to stimulate regular periods — this also reduces the risk of developing endometrial cancer, which is linked to no or irregular periods
• IUS to keep the womb lining thin — this will reduce the risk of developing endometrial cancer but may not stimulate periods

Most women with PCOS can get pregnant after treatment to resolve fertility problems. Treatment usually involves taking tablets at the start of each menstruation cycle for several cycles. If this is not successful, your doctor may recommend injections or IVF (in vitro fertilisation). 

Tablets to treat fertility problems include: 

• Clomifene — this is usually recommended first 
• Letrozole — this is a breast cancer medication but can be prescribed to treat fertility problems
• Metformin — this is used to treat type 2 diabetes but can be prescribed to treat PCOS; it lowers cholesterol, reduces the risk of heart disease and stimulates ovulation

Treatments for hair loss and excess hair growth work by blocking the production and/or effects of male hormones, and include: 

• Combined oral contraceptive tablets, such as co-cyprindiol
• Cyproterone acetate
• Finasteride
• Flutamide
• Spironolactone

The growth of excess facial hair can also be slowed by using eflornithine cream.

Treatments for other symptoms include:

• Acne treatments
• Statins to lower cholesterol levels if you have high cholesterol
• Orlistat to help reduce your weight if you are overweight