Understanding Hair Loss

Smart advice if you're worried that you're shedding more strands than you should be

- BY LISA BAIN

It's an unsettling feeling when you see a layer of hair covering your shower floor after you've bathed. Or maybe you notice a wider-than-normal part when you're blowdrying, or that your brush is filling up with stray strands faster than usual.

Some loss of hair is nothing to fret about. During the usual cycle of hair growth, there's a stage at which strands shed naturally, making way for new ones to grow. “During a normal hair cycle, 90% of the strands are in the growing phase and about 10% are in a shedding phase,” explains board-certified dermatologist Mona Gohara, M.D., an associate clinical professor of dermatology at Yale School of Medicine. “The normal amount of hair loss is about 50 to 100 hairs a day. If you see lost hair expanding beyond that, it’s probably not normal.”

Your first step when you notice unusual or dramatic hair loss should be to see your primary care doctor, says Dr. Gohara—they can run lab tests to determine whether the cause is a metabolic one such as a vitamin deficiency, a thyroid problem, or an autoimmune issue.