How does hair grow?

Hair is made at the base of a hair follicle. There are a thousand hair follicles on your head. Not all of them are working at the same time. Only about 80% of your follicles are producing hair at any one time. The rest of the follicles are asleep or dormant. When dormant hair follicles start working again, they push out an old hair while making a new one. You could lose 50 to 100 hairs in any day. Some of us lose more than that–and don’t get them back again!


What is the flu and why do I need a flu shot every year?Ask a Doctor:What’s a pulled muscle?