Eyebrow Right

What Causes Thinning Hair

The most common reason for thinning hair in women is hereditary hair loss or androgenetic alopecia (AGA). It’s a condition that causes changes to your hair follicles due to genetics, hormones, and age.

If you have hereditary hair loss (AGA), it will cause your hair follicles to shrink over time. So while your hair may still be growing, the quality of that hair will change — getting smaller, finer, and less visible —until it can no longer produce new hair. 

THE ANATOMY OF AN INACTIVE FOLLICLE

An inactive follicle is one that can no longer produce new hair. A common cause for this is hereditary hair loss, or androgenetic alopecia (AGA), which causes follicles to shrink and produce increasingly shorter, finer, and less visible hairs with each growth cycle until follicles are incapable of replacing the hair after shedding.

KEEP TABS ON HEAVY SHEDDING

It’s hard to believe that a woman has on average up to 100,000 strands of hair on her head. When you think of each hair going through a constant cycle of shedding and growth, finding strands here and there makes perfect sense. While it is normal to shed some hair, 50 to 100 per day, make sure you also take note of what’s normal for you.

If you notice a difference in the amount of hair you find on your pillow, in the drain, or on your brush, you may be experiencing hair loss or thinning. Keep in mind that shedding as little as 50 extra strands each day can be a sign of early hair loss. 

HAIR LOSS CYCLE 1: GROWING

People with hereditary hair loss whose hair follicles are still active, will experience the same growth cycle as someone with healthy follicles, but the growth phase of the cycle may be shortened. This cycle begins with anagen, or the growth phase, which lasts from 2 to 6 years.

And while someone with hereditary hair loss may still see their hair growing, their follicles will continue to shrink, causing them to produce finer, shorter, and harder-to-see hairs with each cycle until they can no longer make new hair. 

HAIR LOSS CYCLE 2: TRANSITIONING

Next, the hair enters into a 2- to 3-week transitional phase, or catagen. This is when the cells at the base of the hair stop growing, just as it would in a healthy follicle. 

HAIR LOSS CYCLE 3: RESTING

After the transitional phase, the hair follicle in a person with hereditary hair loss enters a 2- to 3-month resting phase called, telogen — just as it would in a healthy follicle. 

HAIR LOSS CYCLE 4: ATTEMPTING GROWTH

Finally, the follicle will shed the hair and attempt to make a new one. Since hair follicles in a person with hereditary hair loss are continuously shrinking, the damage to the follicles causes them to produce increasingly shorter and finer hairs until they can no longer grow hair at all.