seasons, hair loss

You Lose Less Hair in Winter

Find out how much is normal.

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THE SCIENCE
People lose more hair during the summer and fall compared to the spring and winter, according to a new study in the British Journal of Dermatology.
EXPERT INSIGHT
“It’s normal to lose about 50 to 100 hairs a day and you’ll see more around the shower drain in warmer months,” says study author Shawn Kwatra, M.D., assistant professor of dermatology at Johns Hopkins University. Previous studies involving trichograms—the microscopic examination of hair shifts—have also reported more shedding during summer and fall both in humans and animals.

While scientists aren’t quite sure why we shed differently throughout the year, Kwatra points out that from an evolutionary perspective, hair grows to provide warmth, which is less necessary during the summer. 

THE BOTTOM LINE
While some hair loss is normal, if you suddenly find your hairbrush filled with more strands than normal, or notice it's skewed towards the first half of the year, Kwatra advises talking to your doctor. It could be a sign of too much stress or a nutritional imbalance.