How long does a human hair live for?

Losing hair is a natural part of the hair growth cycle. We lose hair so that new hair can replace it. However, when hair does not grow back as it should, we start to notice thinning hair and a more visible scalp through the hair. In order to understand hair loss, one must understand normal hair growth and shedding cycles.

The hair growth cycle is ongoing, and on an average day, 90% of your hair is in the resting phase while the other 10% is either growing or shedding. Balding occurs when the hair sheds, and no hair re-grows to replace it. Hair is made of keratin, the same material that makes up your nails and the outer layer of your skin. Hair is really a dead structure while the follicular bulb is the growing center. Because the actual strand of hair is not alive, hot curlers, chemical processing, hard plastic combs can cause damage and lead to split ends and fracturing of the shafts.

The hair growth cycle begins with the anagen or growth phase. During this phase cells in the root of the hair divide to add to the hair shaft. Depending on your genetics, the growth phase can last anywhere from 2 to 6 years. As the anagen phase comes to an end, an unknown signal tells the hair to enter the next stage. The hair grows about a fourth of an inch each month, and though it is technically dead, a healthy hair care regimen can keep it looking beautiful while it’s in the anagen phase.