What your hair says about your health

Dry hair? Dull hair? Split ends? These common hair problems might mean more than you think.

You can tell a lot about a person by looking at their hair – and not just their choice of cut, colour and style. Forensic experts have long used hair samples as part of DNA evidence, and a recent study on hair protein says hair alone can be used to accurately identify a person. Outside of the lab, however, you can also study your locks to learn about your overall health — how much stress you’re under, the state of your diet. Here are some pointers for how to “read” your hair.

Are you shedding?
If you’re seeing a few too many strands in your hairbrush or notice shedding every time you run your fingers through your hair, it could be a sign of a nutritional deficiency, says Dr. Sandy Skotnicki, an associate professor of dermatology at the University of Toronto. “Typically, if you are shedding, your iron stores are low,” she says. Some medications such as anti-depressants and birth control list hair loss as a side effect, and usually, it’s temporary.

If your hair loss is significant, it could be alopecia, a condition dermatologists say may be triggered by stress-related, metabolic or endocrine problems. “Usually it’s a response to stress,” says Skotnicki. “Many women lose their hair after they’ve had a baby, for example, which can be traumatic on the body and cause the hair follicles to stop growing. At that time, your body is using its energy to do other things.” Significant hair loss is not something to take lightly, says Dr. Jeff Donovan, a dermatologist and hair loss specialist based in Vancouver. “It needs careful evaluation: I would listen to a patient’s story, determine their health status and examine their scalp to look for underlying problems.”

Related: Anti-aging hair guide: How to volumize thinning hair

Split ends?
We all get a few split ends from time to time, and hair breakage is often caused by overusing heated styling tools or chemical products. But if your hair is extremely weak and dry it’s worth consulting your doctor. Donovan says, “If you find you have dry hair it’s unlikely from dehydration,” so simply drinking more water won’t help. “Patients with persistent dryness can have underlying thyroid abnormalities.” He recommends a blood test to check both thyroid and iron levels. “About 35 percent of pre-menopausal women have low iron and 15 percent of women have thyroid abnormalities which can lead to hair issues.”

Dull hair?
If your normally lustrous mane is looking limp and your blood tests are normal, it could be a reflection of a poor diet, says Donovan. “For some women, hair becomes limp and dull from nutritional issues, so we might look into the possibility of multivitamins.” Your hair is made of a protein called keratin, and if you’re not getting enough protein in your diet, it could weaken your hair.

Related: 53 gorgeous grey hairstyles that will inspire you to ditch the dye

You’re not alone: dandruff affects roughly 50 percent of the population worldwide. “It’s not typically an indication of a health issue,” says Skotnicki. “It seems to be an organism on the scalp that overgrows in some people.” A recent study found that dandruff is more closely linked to the presence of bacteria, not fungi on the scalp as it has long been attributed. Therefore, maintaining the right balance of bacteria can be a key factor in preventing dandruff. If the flakes are yellow and irritation extends to the on the face or back, it could be an indication of the inflammatory skin condition seborrheic dermatitis. Your doctor or dermatologist can recommend a shampoo or topical treatment.

Going grey before 40?
Grey hair is not typically caused by stress, despite what many think. Hair goes grey when your scalp’s colour-producing cells, called melanocytes, stop producing melanin, the pigment that determines its colour. The process is commonly associated with aging. If you start greying before the age of 40, Skotnicki says, “There’s nothing you can do — it’s genetic.” And yet, there is hope: This year, researchers at University College London discovered the gene responsible for grey hair and are confident their findings will make it possible to develop medications to switch it off.

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