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The Sweet Hair After

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

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.

Telogen Effluvium

The name is fancy -- telogen effluvium -- but all it means is increased hair shedding. Lots of hair shedding. For various reasons, many hair follicles enter the exogen stage all at once.

The good news here is that hair lost this way almost always grows back in a few months.

Chemotherapy-Induced Alopecia

Cancer cells grow wildly. Chemotherapy takes advantage of this by killing off cells with out-of-control growth. Unfortunately, there's one kind of normal cell that grows like this: Hair matrix cells.

Chemotherapy forces growing follicles into the catagen stage. The hair shaft doesn't develop properly, so the hair breaks and falls out.

The good news is that when chemotherapy is over, the follicles regenerate. Healthy, new hair grows again. The bad news is that, in the short term, chemotherapy causes near total hair loss.

Alopecia Areata

Sometimes a person's immune system attacks the cells of the growing hair bulb. This autoimmune condition is called alopecia areata.

Just as in chemotherapy, hair follicles are forced into the catagen phase. Hairs break and fall out, usually in patches scattered across the scalp.

Sometimes the immune system attacks only the hair bulb. In this case, the hair follicles regenerate when the immune system is brought under control.

Alopcia areata is not related to a more serious condition known as cicatricial alopecia, in which the immune system attacks the stem cells in the bulge of the folicle. This results in permanent hair loss.

Today's Hair-Loss Treatments: Drugs

By now, many people know that men can buy shampoo with an ingredient called minoxidil. Minoxidil -- originally developed as Rogaine -- fights androgenic alopecia in both men and women.

It's still not entirely clear how minoxidil works. And there's disagreement about how well it works. Used properly -- twice a day, massaged deep into the scalp -- it slows new hair loss. It also promotes new hair growth, although experts disagree about how much.

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