Are your stray hairs everywhere? On your desk, your pillow, clogging your shower drain, and all over your sweater? Here, general internal medicine specialist Dr. Seema Marwaha answers some of the questions about shedding that you’d rather not have to ask.
How much hair do people actually shed, on average?
The average human head has between 100,000 and 150,000 hairs on it. For most people, 90 percent of the hair on your head at any given time is in a growing phase, while about 10 percent is in a “resting” phase. Resting-phase hair falls out to create room for new growths.
It’s not uncommon to offload up to 100 of these resting hairs every day, especially if you’re blessed with a thick coif.
I haven’t counted, but it feels like between what I see in my brush, and what’s constantly stuck to my sweater, I’m losing more than that.
If you notice a big increase in the amount you are shedding, something might be up.
Like nails and skin, hair is very sensitive to any stress placed on the body. When a stressful event happens, your hair is prematurely pushed from the growth phase into a resting stage and sheds more easily. This can last weeks or months, depending on the stressor.
This can happen with emotional issues—like losing your job or getting a divorce. Physical stressors, like illness, lack of nutrition, or significant weight loss can cause you to shed more hair, too. Hormonal changes after childbirth can cause new moms to shed more for months.
What about the products I use on my hair?
Too much shampooing, styling and dyeing can also harm your tresses. Heat and chemicals weaken the hair, causing it to break and fall out. Giving your hair a sabbatical from styling can help a lot.
Okay so how do I know if it’s “just life” that’s causing the shedding, or something more serious?
Give your doctor a heads-up if excess shedding lasts longer than three months.
Chronic hair loss can signify that something in your body is off. The most common causes are deficiencies in iron, vitamin D, vitamin B12 and thyroid problems. Have your doctor rule out more serious issues, like autoimmune diseases and side effects from certain drugs.
What role does genetics play?
Some men and women are predisposed to hereditary hair loss. Men tend to develop a receding hairline or bald patch that begins in the centre of the scalp, while women may notice gradual thinning all over. Your doctor might recommend a pill or cream to slow the process.
And let me guess . . . hormones are involved somehow.
Hair changes as we age because of hormonal fluctuations. Estrogen promotes hair growth and thickness and declines as we approach menopause. This can cause hair to look thinner over time and not grow as long and lustrous as it once did.
Originally published November 2018; Updated October 2019.