Between 50 and 100 hairs fall out of your head each and every day. Run the numbers and that's about 30,000 hairs a year literally down the drain. But don't worry—while your plumbing surely notices, chances are your online dating pic doesn't. You have a whopping 100,000 hair follicles on that scalp of yours, and they're in a constant cycle of growth, rest, and release that can last anywhere from two to six years.
So aside from genetics, what makes your head to shed faster than usual? Common causes are stress, the foods you eat, and the season—but maybe not for the reason you think.
Fortunately for the months ahead, the rumor that scalps get drafty in the winter is flat-out false. In fact, one six-year study from the University Hospital of Zürich shows that people actually lose the least amount of hair in the winter.
A growing body of research suggests this might be a leftover evolutionary adaptation. (Just think how thick Fido's fur gets in the winter.) For instance, melatonin, notorious for making you drowsy during the dark days of winter, actually helps regulate hair cycles, spurring longer, and warmer winter coats in mammals—opposable-thumb-wielding species included.
Still, there are a few cold-weather caveats to consider. Dry scalps are unhealthy, and grow brittle, breakable hair, which excessive friction—like pulling on and off a too-tight hat—can snap or uproot altogether. (In fact, according to research published in the International Journal of Dermatology, caps are a significant contributor of hair loss among nurses.)
Instead of covering your head with an endless array of hats (they only create cowlicks, anyway), treat your hair right with products that are designed to protect your scalp and strands from dry weather and even dryer indoor heat. This winter, forget about having good-hair days and start focusing on having a good-hair season.