Tressed out: Is your hair thinning?

Pluck, wax, sugar off and shave — you’ve tried every trick in the book to keep unwanted hair at bay. But, as Murphy’s beauty law would have it, you’re suddenly losing it in the wrong place: on your head. Your usually lavish locks are falling fast, and your brush looks like a bird’s nest. While most of us think that only men or older people are afflicted with sparse or thinning strands, an estimated 40 to 50 percent of women experience hair loss by the time they reach menopause, according to the Canadian Hair Research Foundation.

We all lose a little: It’s normal to cast off roughly 100 hairs a day — a hardly noticeable number, given that the average head boasts 100,000 or more. It’s just part of the process: Each hair you have cycles through a growth stage (three to seven years) and a resting period (about three months). “If the hair is in an area that is not destined to go bald or thin out, it grows back exactly the same way it did in the first place,” says Dr. Walter Unger, an associate professor of derma­tology at the University of Toronto. “This goes on over and over again throughout your lifetime.”

But for those predisposed to go bare, the hair comes back progressively shorter and finer. In many cases, genes are the culprit. The most widespread type of hair loss for both men and women is hereditary: androgen­etic alopecia, or pattern baldness. Some people inherit hair follicles that are just more sensitive to a naturally occurring hormone called DHT, which is formed when testosterone hooks up with an enzyme found in the oil glands of the hair follicles. The problem is, DHT has the ability to shrink those follicles over time. Pattern hair loss affects a whopping 38 percent of females, says Dr. Jerry Shapiro, director of clinical research in the Hair Research Laboratory at Vancouver General Hospital and the University of British Columbia’s department of dermatology. It’s more likely to happen post-menopause (when levels of estrogen — which counterbalances DHT — drop), but it can hit anytime after puberty.

'Pattern hair loss affects a whopping 38 percent of females,' says Dr. Jerry Shapiro, director of clinical research in the Hair Research

Even if you’ve won the lush-hair lottery, you could still find yourself suddenly sparser. Everything from emotional stress, a high fever and childbirth to crash dieting, nutrient shortages and certain drugs (like the birth control pill) can spark a condition called telogen effluvium, the
second-most-common type of hair loss. It’s marked by abrupt shedding all over the head two or three months after a shock to the system. Essen­tially, a higher-than-usual number of follicles fast-forward into fallout mode, so you end up losing 300 or more hairs daily instead of the typ­ical hundred.