Your Hair Is Doing Much More Than You Think It Is

Hair sits at the top of the list of attributes that collectively form the identity we present to the rest of the world. Each of the 100,000 hair follicles on your scalp and many others across your body, a form of expression.

These strands are made mostly of keratin, a protein also found in your nails. But they’re much more than that; hair is a wonder of biology. Keep reading to discover all that your hair can tell you about your health.

Hair protects you

You’ve probably heard of the gut microbiome. Well, you also have a hair microbiome. Within each follicle, microbes are crowding out harmful germs and reducing the risk of infections. They might even help your hair grow and amplify your hair color.

When you get cuts or scrapes, hair also helps heal these wounds. Specifically, stem cells inside your hair follicles are mobilized to migrate to the wound and to transform into new skin cells. Once the wound heals, the stem cells return to their original job, growing hair.

Motion detectors for your brain

Your hair follicles are wrapped in nerve endings, which enables them to act like motion detectors for your brain. If, say, a gnat should drift near your eyes, your lashes will sense it and trigger a blink.

Hairy skin has nerves that connect to the brain’s emotion centers. This is why a gentle caress can feel pleasant. And why waxing or plucking is especially painful, since you’re ripping the hair out of the follicle.

Hair follicles also contain smell and bitter-taste receptors that appear to influence hair growth. Early research suggests that certain fragrances seem to stimulate hair growth while others might inhibit it, but more data is needed.

Hair tells time, too

Your brain has an internal clock. So does each hair follicle. It helps to keep hair growing, winding down, resting, and shedding in repeating cycle. Researchers believe it may explain why hair tends to grow faster in the morning than at night. Because the clock genes inside the follicles are synchronized to your body’s 24-hour clock, experts believe that a few hair samples may be all that’s needed in the future to track some sleep disorders.

A sign that’s something’s wrong

Hair is the second-fastest growing tissue in the body. (Bone marrow is the first.) This is how a centimeter of hair captures about a month’s worth of biological data, which is why it’s sometimes used to test for drugs. Hair follicles suck up toxic compounds, much like the kidneys, and deposit them in your dead hair shaft. Hair can also capture chronic stress and medication adherence. 

This pace of growth requires a lot of energy. So sudden hair loss often serves as a sign of stress or illness. It can also be caused by nutrient deficiencies, high fevers, thyroid dysfunction, sudden weight loss, major surgery, and childbirth. Distressing as this can be, the hair usually grows back in three to six months.

Some hair shedding is inevitable; we lose about 50 to 100 strands a day.

Whether you love your hair or are consistently frustrated by it, it is, scientifically speaking, a true marvel.