Why Your Hair Is Thinning

Certain factors—some controllable, others not—can decelerate the speed at which your hair grows and contribute to larger problems like thinning and hair loss. According to Las Vegas dermatologist Alison Tam, MD, “Many of the problems that cause a change in hair growth are considered ‘stressors’ to the follicle. Since hair follicles are not necessary for keeping the body alive, it goes into the resting phase (and then sheds) when exposed to the stressor.” If hair falls out earlier than it should, it may grow back thinner because the density has changed.

Thinning hair doesn’t just happen to men. Women can experience it too. “When hair thins, the follicles produce finer hairs over consecutive cycles,” says Elizabeth Cunnane Phillips, trichologist at the Philip Kingsley Clinic in New York. “The diameter of the hair fiber becomes thinner than those that were previously made and the growth cycle becomes shorter.”

When women notice thinning, it tends to occur more toward the crown of the head. “Women notice thinning and/or hair loss about 20 years later than men. Sometimes thinning starts in your 30s or 40s and sometimes it doesn’t occur until much later,” says Dr. Tam. When thinning becomes predominant, it’s because more hairs have shifted into the catagen and telogen phases. “The hairs shrink and become smaller and smaller until they are very fine and light in color,” says hair restoration specialist Dr. Craig L. Ziering. 

The condition of your hair can affect texture, making it look thin even if it physically isn’t. “If the hair is damaged and split, it can start to look thin. Fraying ends give the look of thinner hair and achieving good hair volume can become difficult, too,” says Britney Huinker, owner of the Argyle Salon & Spa in Los Angeles. 

For some, oil may cause thin patches. “When there is too much oil on the scalp, it can drown the follicle, causing growth to come to a halt and forcing the hair to die early,” says Karim Dossa, national educator for Rene Furterer. You can gauge how thin (or thick) your hair is at any given point based on the density of the hair at the root. There’s no preset standard as to what the norm is for thickness or thinness since it’s based on the individual.

Do you have any styling tips for thinning hair?