Family doctor

What is hirsutism?

Hirsutism in women is the growth of hair in a typical male distribution. This hair may grow on the chin, upper lip, side of the face, breasts, stomach and thighs. The growth of thick, dark hair in these places may be accepted as normal by some cultures. But in others it can cause a great deal of distress for the woman.

This growth is caused by male hormones (androgens). The most powerful of these male hormones is testosterone. All women normally have a certain level male hormones circulating in their blood.

How does hair grow?

Each hair on your body or head grows to a set length from a bud at its base. Pigment is added to these growing cells to darken the hair. The average rate of hair growth ranges from 0.2mm per day for hair on the thighs to 0.5mm per day for hair on the scalp. After a hair ends its growth phase it drops out.

Each body hair grows for up to three months and each scalp hair for up to three years. Hair growth then stops and the hair becomes less dark. During this phase a second hair bud develops to grow a new hair to start the next cycle. The new hair then rests until the old hair has fallen out.

At any one time about 86% of your hair follicles are growing, 1 % have stopped growing and 13% are moulting.

Where does hair grow on the body?

Except for the palms of the hands and soles of the feet, fine hair is present almost all over the body. Testosterone acts like a key going into a lock on the hair root to change fine body hair to thicker, longer and usually darker hair.

Hair growth in women occurs in the following major areas:

The lower pubic triangle and under the armpits\t

Pubic hair appears about two years before hair under the armpits. It appears in girls in the early to mid teens. This growth of hair is caused by the production of male hormones from the adrenal glands which are small triangular shaped glands which sit on top of the two kidneys.\t

The face and the rest of the body

(This includes the upper pubic triangle, on the tummy and around the sweat glands). These hairs also grow in response to male hormones but are less sensitive to the effects of male hormones than hairs on the pubic area or under the armpit. These hairs need higher levels of male hormone to make them grow.

Hair growth is more likely to occur in these areas in men because men have higher blood levels of testosterone than women. Higher levels of male hormones also result in the development of oily skin and acne. While men more commonly have hairy legs, growth of hair on the arms is similar in men and women.

The scalp

Scalp hair is different from all other hair because its growth does not depend on male hormones. Surprisingly it appears that male hormones make some people develop baldness by causing thick, dark scalp hair to be changed back to fine hair.\t

Hirsutism - you are not alone

This means you share this problem in common with a lot of women and you are normal. Only very rarely is hirsutism a sign of a serious hormone abnormality that requires further investigation. In these rare cases the patient may also have been experiencing changes in the genitals, enlargement of the clitoris, loss of hair from the temples and reduced size of the breasts.

In the United Kingdom 18 percent of women have hirsutism on the chest, 28 percent on the face, 35 percent on the tummy and 70 percent on the legs.

Where do male hormones come from in women?

Male hormones causing hair growth in females come from three sources:

• The adrenal glands
• The ovaries
• From fat which converts other hormones to male ones. In a baby in the womb, the adrenal glands secrete male hormones but this stops shortly after birth and secretion is switched off until puberty. As puberty approaches in the early teens, the adrenal glands "wake up" and start to secrete male hormones again. The adrenal glands probably cause the growth of pubic hair and hair under the armpits.

Following this, the ovaries start to work and make both male and female hormones. This is marked by the onset of periods. Following the menopause, when the ovaries usually stop working, the ovaries still make testosterone in 50% of women.

Why are some women hirsute and others not?

Not all women who have high testosterone develop unwanted hair. Hirsutism is caused by an increased sensitivity of the skin to the activity of normal or raised levels of male hormones. Therefore, although this 'sensitive' skin will remain with you all your life, treatment is available to block the actions of male hormones on the skin.

Types of hirsutism:\t

Hirsutism can range from very mild to severe. Some women who are hirsute have normal levels of male hormones. This is called idiopathic hirsutism (no exact cause known).

Some have small increases in levels of male hormones. One cause of this is as part of the polycystic ovarian syndrome.

In rare cases women can have tumours of the ovary and adrenal, when hormone levels reach that of a man.

How is my unwanted hair investigated?

If your hirsutism is mild, has recently appeared and is not progressing, your doctor will have you take a blood test to find out your testosterone levels.\t

• If this is normal you will probably not need any further tests.
• If the level is mildly increased the doctor will probably suggest you have an ultrasound scan of the ovaries. (An ultrasound scan uses soundwaves to make a picture of the insides of your tummy. It is most often used to take a look at the baby in a mother's womb).
• If your testosterone is significantly high, your hirsutism has appeared recently and you've experienced genital changes, your doctor will probably advise you to have a "catheter study". This involves the insertion of a fine plastic tube (catheter) into a vein in the groin so that your doctor can take blood samples for measurement of hormone levels from the ovaries and adrenal glands to find out if you have any tumours. Such tumours are rare. In this case, this and other tests, will be explained by your doctor in greater detail.

How can my unwanted hair be treated?

If your hirsutism is only mild and you have been reassured that there is no serious hormonal abnormality you may feel that you do not need any treatment. Or, you may like to try local measures such as shaving and electrolysis.\t

There is no evidence to suggest that shaving increases the rate of hair growth. However plucking the hair should be avoided as this stimulates a new cycle of hair growth.\t

If you have tried some of these measures and you are still uncomfortable with your level of unwanted hair you might like to try drug treatment. However, as with all drugs any risks of treatment should be weighed against any likely benefit.\t

It is important for you to know that drug treatment is unlikely to have any visible effect on your unwanted hair before three months (the average time of the growth phase of body hair). When you stoptaking the drug your hirsutism will come back, so you will need to continue the treatment indefinitely.

There are two main drug treatments. Both of these drugs block the effects of testosterone.\t

Cyproterone acetate blocks the activity of testosterone. It is given in doses of 100mg daily from day 5-15 of the cycle along with a high dose of the female hormone, oestrogen. This treatment is given every month. This is effective in about 70% of patients.

It is also present (in a lower dosage) in the combined contraceptive pill Diane, which may be a useful treatment, particularly if contraception is also desired.

In children given cyproterone acetate there is evidence that the drug may switch off the adrenal glands but this does not happen in adults. However, the drug has side effects and there are also risks associated with the prolonged use of oral oestrogen. In adults this drug may cause a marked loss of libido (wanting sex) and dryness of the vagina.

Spironolactone 200mg daily achieves an improvement in 80% of patients with fewer side effects. One in four patients may have increased frequency of their periods or bleeding in the middle of the month. If this happens in your case you can be treated with the addition of the oral contraceptive pill to regulate your periods. Alternatively your doctor may adjust your dosage. Spironolactone is usually well tolerated by most patients.

It is important that you don't get pregnant while taking either of these drugs as there is a risk of the treatment affecting the health of your unborn child.

Is my fertility affected if I have hirsutism?

Fertility is usually normal in patients with idiopathic hirsutism but may be impaired in patients with polycystic ovarian syndrome, particularly if the periods are irregular.

If you are taking either of the two drugs mentioned above and you want to get pregnant, you will have to stop your treatment.