You can now read 10 articles in a month for free on BostonGlobe.com. Read as much as you want anywhere and anytime for just 99¢.

The Boston Globe

Health & wellness

Health answers: Hair that comes when you get older

Q. Why do I get hair in places like my ears and shoulders as I age?

A. It’s a common joke that as hair thins on men’s scalps, it springs up in new places below — including the ears, nose, shoulders, chest, and back. Thomas E. Rohrer, a Chestnut Hill dermatologist and member of the board of directors of the American Academy of Dermatology, says, “the hair was there to begin with, but it changes with age.”

Continue reading below

Fine hairs called vellus hair grow all over our bodies except a few places like the soles of the feet and palms of the hands. During and after puberty, some of this hair transforms into thicker, darker “terminal” hair, to a greater extent in men than in women. Rohrer explains that with aging the normal growth cycles of hair — growth, resting, and falling out phases — get out of whack. The result: some hairs grow longer before being shed (hence the bushy eyebrows in older men), and some of the downy vellus hair turns into the more noticeable terminal hair.

The cause of this transformation isn’t entirely known. “We think that one of the reasons it happens is in response to prolonged testosterone,” he says; even though testosterone levels don’t rise, the hormone may have a cumulative effect.

This effect is not as common in women, and studies have found that body hair becomes less noticeable for some women as they age. But aging and hormone changes with menopause often lead to more noticeable facial hair.

Have a question? E-mail globeanswers@gmail.com.

You have reached the limit of 10 free articles in a month

Stay informed with unlimited access to Boston’s trusted news source.

  • High-quality journalism from the region’s largest newsroom
  • Convenient access across all of your devices
  • Today’s Headlines daily newsletter
  • Subscriber-only access to exclusive offers, events, contests, eBooks, and more
  • Less than 25¢ a week