What your hair is telling you about your health

Photo courtesy iStockphoto: Woman with mirror, Prostock-Studio

From head to toe, humans are covered with hair. While a lot of your body hair is not noticeable, it’s working to protect you: Eyelashes and eyebrows keep things out of your eyes. Tiny hairs stop things from getting in your ears and nostrils. Hair on your legs and armpits can keep your skin from chafing.

But the hair on top your head? Other than protection from the sun and cold, it doesn’t serve a lot of purpose. Sometimes, though, it can tell you things about your health.

The most common health concern related to hair is when it’s no longer there, AKA hair loss. Thinning, balding or receding hair may not always be welcome, but it’s usually a natural aging process, determined by your genes. Some regular hair loss is normal, so there’s no need to be alarmed if you see a modest amount of hair in your brush or shower drain.

However, rapid changes and hair loss in areas not generally associated with regular baldness patterns can be a sign that something is wrong, says David Pariser, MD, a Virginia dermatologist.

“The health of the hair is often associated with the health of the body,” Pariser says.

Hair shedding can be a symptom that your thyroid isn’t working right, or that you have nutrient imbalances in the body, such as an iron deficiency. Because of hormonal changes, hair shedding is also common during and after pregnancy, though it’s usually temporary.

Although less common, a condition called alopecia areata can cause hair loss. It can occur when your immune system attacks your body. People with the condition can have patches of baldness anywhere on their body, including their scalp, eyebrows and chin. Coin-sized bald spots are most common, but sometimes people can become completely bald or lose all their body hair. Alopecia areata can happen at any age, but commonly starts in childhood or teen years.

Sometimes hair loss can be related to mental health. Researchers have found that chronic stress can cause hair loss. Another mental heath-related issue is trichotillomania, or hair-pulling disorder, in which someone has recurring urges to pull out their hair. A professional therapist can help you work through these types of issues, and your hair will usually come back.

Surprisingly, hair that looks greasy or unmanaged is not necessarily a symptom of poor health. What people consider healthy-looking hair is more about social norms.

But if you have any concerns about hair thinning, loss or breakage, it’s a good idea to mention them to your health team.

While your doctor can help you sort out which issues need medical intervention, you have another ally who can help you detect problems with your hair or scalp — your barber or stylist. They can tell you if something you’re doing, such as using high heat or pulling your hair back tightly, is causing hair loss or other problems.

Many of the issues people associate with hair are actually related to their scalp. Your skin cells renew themselves about every 28 days, and they have fewer avenues for removal under your hair.

The most common scalp condition is dandruff, in which small bits of your skin flake off, sometimes on your shoulders. Dandruff can be itchy and annoying and get worse in dry winter months, but it is usually treatable with special over-the-counter shampoos.

Scalp irritation could mean you are allergic to something in a hair product. Your scalp can also be inflamed by psoriasis or an infection, so if it doesn’t get better when you change products, talk to your health team.

Thick hair may seem ideal, but it can hide health issues on the scalp or ears. Your locks might be covering up signs of skin cancer, for example. It can be hard to detect these issues on your own, but having a regular barber or stylist can help you keep an eye on things.

• Copyright The Nation’s Health, American Public Health Association