Slideshow: What Your Hair & Scalp Say About Your Health

Does Bad Hair Mean Bad Health?

Is your hair trying to tell you something about your health? Maybe. Some conditions and medications affect your body as well as your hair. In other cases, you may just need to take better care of your hair or scalp. Use this pictorial guide to see what separates myth from fact when it comes to your health and your hair.

White Flakes Pose No Health Risk

Dandruff isn't contagious. So how do you get it? Doctors aren't sure, but one theory is that it may be due to an overgrowth of a fungus. Other possible triggers include skin that's either too dry or too oily, shampooing either too often or not often enough, and having eczema or psoriasis. While it's embarrassing – and the itching can be bothersome -- dandruff isn't harmful.

Tips for Dandruff Treatment

To decrease the buildup of dandruff's dead skin cells, try using an anti-dandruff shampoo daily. Leave shampoo on for 5 minutes, then rinse well. You may need to try several dandruff shampoos to find one that works best for you. If one stops working, try another. If that doesn't help, call your doctor.

Yellow Dandruff?

If the dandruff flakes you see are greasy and yellow, you may have seborrheic dermatitis. It's an inflammatory skin condition that can occur where there are lots of oil glands, like the scalp and face. Though seborrheic dermatitis is related to hormones, fungus, and even some neurological problems, it's treated the same as dandruff: with anti-dandruff shampoos. Severe cases may need a prescription steroid or antifungal medicine.

You May Shed More Than You Think

It's not a perfect measure, but some experts estimate that we may shed up to 100 or more hairs a day. That's not cause for alarm, nor does it mean you're going bald. About 90% of your 100,000 hair follicles are growing at any given time. The other 10% are in a resting (telogen) phase, and the hair falls out after about 2 to 3 months. It's replaced by new hair, and the growth cycle starts over again.

What Causes Telogen Effluvium?

A shock to your system -- surgery, giving birth, some medications, crash diets, severe stress, thyroid problems -- can push hair into its resting, or telogen, state. About 2 months later, you may see hair falling out -- a condition called telogen effluvium, sometimes described as hair “coming out in handfuls.” In most cases, new hair starts growing right away. Your doctor should determine if your telogen effluvium needs treatment.

An Attack on Hair Follicles

In alopecia areata, your immune system mistakenly attacks hair follicles, causing hair to fall out -- often suddenly. Most people will have one or two bald patches, but in some cases all body hair falls out. Alopecia areata isn't harmful, but it can be tough psychologically. Hair may grow back on its own or with treatment. Unfortunately, some people don't respond to treatment and may experience repeated hair loss and regrowth.

Genes Cause 90% of Male Hair Loss

Though hereditary, the trait may be more influenced by your mother's family than your father's. So a look at your maternal grandfather's locks may give you a better clue about the future of yours. Male pattern baldness often starts with receding hair at the temples, then on the crown, leaving a horseshoe-shaped ring of hair around the sides of the head. Medications to slow hair loss include Rogaine (minoxidil) and Propecia (finasteride).

How Female-Pattern Baldness Happens

Hair loss in women tends to mean hair thinning all over the head. Unlike men, women rarely go bald, and they tend to lose hair more slowly than men do. Other myths: Longer hair won't put a strain on the roots, causing more to fall out. Nor will shampooing pull hair out -- it just gets the ones that were falling out already. Women's Rogaine (minoxidil) or prescription medications may help preserve hair.

Avoid Sun Damage to Hair

Too much sun can turn your hair into a brittle, dry mop that breaks and splits easily. And if you already have thinning hair, you risk a sunburn on your scalp. Choosing hair care products with sunscreen provides some protection, although it can be hard to coat your hair evenly. That's why it's a good idea to wear a hat when you're out in the sun -- especially if your scalp is exposed.

Luscious Locks Need Nutrients

Could a crash diet cost you your hair? In extreme cases, it could. Your hair needs protein and iron to stay healthy, along with omega-3 fatty acids, zinc, and vitamin A. Very low-cal diets are often lacking in these nutrients and can stunt hair growth or leave hair dull and limp. If the nutritional deficiency is big enough -- like for someone with an eating disorder -- hair can fall out.

A Hair- and Heart-Healthy Diet

Keep hair shiny by eating salmon for omega-3 fatty acids; spinach and carrots for vitamin A; brazil nuts for selenium; and oysters and walnuts for zinc. All help maintain scalp and hair health, as do low-fat dairy, whole grains, and vegetables. Double the results: foods good for your hair are also good for your heart.

Premature Gray Hair Is Genetic

Going gray isn't always related to aging. If you're not yet 40 and see more than a few gray hairs, chances are it runs in your family. Gray usually isn't a sign of poor health, though anemia, thyroid issues, vitamin B12 deficiency, and vitiligo can cause premature graying. You can highlight or color hair to cover the gray, but beware: some people are sensitive to the dye's chemicals. The result is an itchy, burning scalp.

Traction Alopecia Damages Follicles

Pulling hair too tight -- as can happen with ponytails, braids, and cornrows -- can damage hair roots and cause hair to break or fall out. Hair extensions and hairpieces can sometimes cause traction alopecia, too, because their extra weight pulls on existing hair. Changing your hairstyle usually lets hair grow back. Pulling hair back tightly for a long time, though, can lead to permanent hair loss

Overstyling Weakens Your Hair

Blow drying, using a flat iron, bleaching, even over-brushing -- all can damage the outer layer (cuticle) of your hair. When the inner core of hair is exposed, your locks become dry and dull. Although it doesn't cause any permanent health damage, you can overstyle to the point that your only option for healthy hair is to cut it off and start over. When it comes to your hair, doing less leads to healthier tresses.

A Surprising Side Effect

Among the medications that list hair loss as a side effect: Coumadin (warfarin); Lopid (gemfibrozil); antidepressants; beta-blockers; non-steroidal anti-inflammatory drugs (NSAIDs); and drugs for gout, arthritis, birth control, and high blood pressure. Usually, hair grows back when the medication is stopped, but some drugs may cause permanent hair loss, or trigger male or female pattern hair loss. Ask your doctor about possible side effects.

Scalp Massage Feels So Good

There's no evidence that massaging your scalp will slow hair loss or improve any scalp conditions -- but it can do wonders for your brain. Your scalp is covered with nerve endings that make it super-sensitive to touch. Rubbing your scalp increases blood flow and releases tension. It also triggers your brain to release feel-good hormones like dopamine and serotonin.

Hair Analysis Not Reliable

Some companies claim they can analyze hair clippings to see if you are deficient in vitamins or have health problems. While hair analysis can detect some poisons like lead or arsenic, there are no testing standards. Labs may report different findings from the same hair sample. And everything from air pollution to shampoo can change your hair's mineral makeup. The American Medical Association is against hair analysis to determine treatment.

More Reading on Skin and Hair Care

• Hair Loss
• Dandruff
• Dandruff: Who Gets It?
• Ringworm on Scalp