Alopecia is the general medical term for hair loss. There are many types of hair loss with different symptoms and causes.
Some of the more common types of hair loss are described below, including:
Male-pattern baldness is the most common type of hair loss, affecting around half of all men by 50 years of age. It usually starts around the late twenties or early thirties and most men have some degree of hair loss by their late thirties.
It generally follows a pattern of a receding hairline, followed by thinning of the hair on the crown and temples, leaving a horseshoe shape around the back and sides of the head. Sometimes it can progress to complete baldness, although this is uncommon.
Male-pattern baldness is hereditary, which means it runs in families. It's thought to be caused by oversensitive hair follicles, linked to having too much of a certain male hormone.
As well as affecting men, it can sometimes affect women (female-pattern baldness). During female-pattern baldness, hair usually only thins on top of the head.
It's not clear if female-pattern baldness is hereditary and the causes are less well understood. However, it tends to be more noticeable in women who have been through the menopause (when a woman's periods stop at around age 52), perhaps because they have fewer female hormones.
Alopecia areata causes patches of baldness about the size of a large coin. They usually appear on the scalp but can occur anywhere on the body. It can occur at any age, but mostly affects teenagers and young adults.
In most cases of alopecia areata, hair will grow back in a few months. At first, hair may grow back fine and white, but over time it should thicken and regain its normal colour. Some people go on to develop a more severe form of hair loss, such as:
Alopecia areata is caused by a problem with the immune system (the body's natural defence against infection and illness). It's more common among people with other autoimmune conditions, such as an overactive thyroid (hyperthyroidism), diabetes or Down's syndrome.
It's also believed some people's genes make them more susceptible to alopecia areata, as one in five people with the condition have a family history of the condition.
Alopecia areata can occur at any age, although it's more common in people aged 15-29. It affects one or two people in every 1,000 in the UK.
Scarring alopecia, also known as cicatricial alopecia, is usually caused by complications of another condition. In this type of alopecia, the hair follicle (the small hole in your skin that an individual hair grows out of) is completely destroyed. This means your hair won't grow back.
Depending on the condition, the skin where the hair has fallen out is likely to be affected in some way.
Conditions which can cause scarring alopecia include:
Scarring alopecia occurs in both males and females, but is less common in children than adults. It accounts for about 7% of hair loss cases.
Anagen effluvium is widespread hair loss that can affect your scalp, face and body.
One of the most common causes of this type of hair loss is the cancer treatment chemotherapy. In some cases, other cancer treatments – including immunotherapy and radiotherapy– may also cause hair loss.
The hair loss is usually noticeable within a few weeks of starting treatment. However, not all chemotherapy drugs cause hair loss and sometimes the hair loss is so small it's hardly noticeable.
It may be possible to reduce hair loss from chemotherapy by wearing a special cap that keeps the scalp cool. However, scalp cooling is not always effective and not widely available.
In most cases, hair loss in anagen effluvium is temporary. Your hair should start to grow back a few months after chemotherapy has stopped.
Telogen effluvium is a common type of alopecia where there is widespread thinning of the hair, rather than specific bald patches. Your hair may feel thinner, but you're unlikely to lose it all and your other body hair isn't usually affected.
Telogen effluvium can be caused by your body reacting to:
In most cases of telogen effluvium, your hair will stop falling out and start to grow back within six months.
More common types of hair loss, such as male-pattern baldness, don't need treatment because they're a natural part of ageing and don't pose a risk to your health.
However, any type of hair loss can be distressing, so you should see your GP if you're worried about it.
Your GP should be able to diagnose your type of hair loss by examining your hair. They can also discuss possible treatments with you so it's advisable to visit your GP before trying a private consultant dermatologist (skin care specialist).
If you want treatment for male-pattern baldness for cosmetic reasons, two medications called finasteride and minoxidil can be used. Minoxidil can also be used to treat female-pattern baldness.
However, these treatments don't work for everyone and only work for as long as they're continued. They are not available on the NHS and can be expensive.
Alopecia areata is usually treated with steroid injections, although it's sometimes possible to use a steroid cream, gel or ointment. A treatment called immunotherapy may also be used. This involves stimulating hair growth by causing an intentional allergic reaction in the affected areas of skin.
If you have significant hair loss of any type, you may decide to wear a wig. Wigs are available on the NHS, but you may have to pay unless you qualify for help with charges.
There are also some surgical options for hair loss, including a hair transplant and artificial hair implants.
Read more about treating hair loss.
Hair loss can be difficult to come to terms with. The hair on your head can be a defining part of your identity. If you start to lose your hair, it can feel as if you're losing part of your identity. This can affect your self-confidence and sometimes lead to depression.
Speak to your GP if you're finding it difficult to deal with your hair loss. They may suggest counselling. You may also benefit from joining a support group or speaking to other people in the same situation – for example, through online forums.
A number of charities, such as Alopecia UK, have support groups and online forums where you can talk to others who are experiencing hair loss.
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