Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Hair Loss Health Center

Font Size

The Sweet Hair After

Future Hair-Loss Treatments Promise What's not Hair Today will Be Hair Tomorrow.

What We Know About Hair continued...

Hair growth goes through several distinct stages:

  • Anagen. The growth phase of hair. An unknown signal tells follicle stem cells to do their thing. Next, the permanent part of the follicle -- the dermal papilla -- gives the "go" signal to hair matrix cells. Those cells grow wildly and become pigmented, creating a new hair shaft. At any given time, 90% of hair cells are in this stage.
  • Exogen. The new hair shaft pushes the old, dead hair shaft out of the skin. The old hair falls out.
  • Anagen finished. The new hair extends beyond the surface of the skin and keeps growing. The hair shaft fully matures.
  • Catagen. The lower two-thirds of the follicle shrivels up and is destroyed. The dermal papilla remains attached to the regressing follicle.
  • Telogen. The withered follicle rests. It waits for a signal telling it to start all over again.

Losing hair is part of a normal cycle of growth and replacement. Hair follicles go through the growth and resting cycle in a nonsynchronized fashion. But sometimes things go wrong.

Common Hair Loss Problems: Androgenetic Alopecia

Most of us, when we think of hair loss, think about aging men. Nearly all men eventually get that receding M-shaped hairline and thinning hair on the top of the head, also known as male pattern baldness. It's called androgenetic alopecia, and it's caused by a by-product of testosterone called DHT.

Aging women have a similar problem. Their hair gets thin, although it's not clear that this is necessarily caused by sex hormones.

What is clear is that the same thing happens in aging men and women. Hair follicles get smaller. The anagen stage of hair growth gets shorter, and the resting (telogen) stage gets longer. The result: Thin, very short hairs -- and many follicles empty of hair shafts.

Why is this pattern of hair loss only in the front and on top? That's where hormone-sensitive follicles live. The follicles on the sides and back of the head aren't affected by DHT and usually stay healthy.

Today on WebMD

hair in hairbrush
Ways to go about it naturally.
Young woman with thick curly hair
Causes and solutions.
man with thinning hair
How to keep the hair you have.
Closeup of Hairbrush with Hair Loss
Understand the basics.
Mens Hair Loss When To Start Treatment
A Dermatologist Talks About Hair Loss
Rogaine And Propecia For Hair Loss
Woman looking at thinning hair in hand mirror
Balding man in mirror
Close up of comb in woman's hair
Young woman with thick curly hair
hair problems