Countdown to Hair Loss

The men washed their hair three mornings in a row with Neutrogena T/Sal shampoo. On the fourth day, they were issued identical combs and instructed to comb their hair forward over a towel or pillowcase of contrasting color. They were then asked to count the hairs that had dropped out. This comb-and-count procedure was repeated on the next two days and the number of hairs was validated under a microscope.

After six months, the participants repeated the full procedure.

Based on these results, the authors concluded that losing 10 hairs is "normal." In younger men (aged 20 to 40), the shedding range was 0 to 78 hairs with a mean of 10.2 hairs. In the older men, the range was 0 to 43 hairs with a mean of 10.3 hairs.

Here are instructions on how to perform the count:

Comb your hair for 60 seconds over a pillow or sheet of contrasting color before shampooing. Pull the comb from the back top of the scalp forward to the front of the scalp for 60 seconds. "That 60 seconds allows you to dislodge any of the resting hairs that are supposed to be shed," Miller said.Repeat the procedure before three consecutive shampooing sessions, always using the same comb. Count and record the number of hairs in the comb and on the pillow or sheet. Repeat the procedure every month and discuss results with your dermatologist.

The study was funded by Merck & Co. and Miller has received consulting fees from drug company Pfizer Inc.

The authors will be releasing comparable data for women in the near future, they said.

When to start panicking over hair loss? Miller counsels men who lose more than 50 hairs a day (as counted in the 60-second period) to check with their physician.

"The hair acts like a window to the inside of the body," he said. "If there's something going on inside the body that is not right, for example, low thyroid output or low iron, your hair can react by shedding more. So if you notice that you're shedding a lot of hair on the 60-second hair count, it would be worthwhile to be evaluated by physician to rule out underlying medical causes."

Sudden changes in the amount of hair you lose should also be evaluated, he said.

More information

Visit the American Academy of Family Physicians for more on hair loss.

SOURCES: Jeffrey J. Miller, M.D., department of dermatology, Penn State College of Medicine, Hershey, Penn.; Doris Day, M.D., attending physician in dermatology, Lenox Hill Hospital, New York City; June 2008,Archives of Dermatology