The risk of suffering a torn artery at a beauty salon is even more remote, but Marilyn Noonan, 47, of La Jolla, California, is proof that it can happen.

Two years ago, she was getting ready to go to a dinner party when she looked in the mirror and noticed that one pupil was much larger than the other. “I’m in the insurance business and had just been to an educational seminar on strokes, so I knew that pupil asymmetry wasn’t good,” she says.

Marilyn felt fine, but she called a neurologist friend anyway. The second question he asked her was, “When was the last time you had your hair done?” Her answer: Just a few hours ago. “He said, ‘Marilyn, you need to get to the hospital right away,'” she recalls.

An MRI revealed a tear in her carotid artery. Fortunately, a large clot hadn’t yet formed, so Noonan’s doctors put her on blood-thinning medication for six months until the artery healed. “She was lucky,” says Shirley Otis, M.D., her neurologist. “She could very easily have had a stroke.”

The most likely cause of the tear — tilting the neck back too far during a salon shampoo — is simple to avoid, Otis adds. “Make sure there’s a towel or some other support under your neck so you don’t have to tilt so far,” she says. Researchers at the University of Medicine and Dentistry of New Jersey reported several years ago that, while tilting your head backward into a sink while shampooing can alter blood flow to the brain, using a support minimizes the problem.

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