Hair Loss in Men and Women (cont.)
How is hair loss classified?
There are numerous ways to classify hair loss. One useful way has been to classify hair loss by whether the loss is localized (small area) and patchy or whether it affects large areas or the whole scalp (diffuse). Other medical classifications for hair loss include scarring versus non-scarring hair loss and are beyond the scope of this article.
Patchy hair loss
Some conditions produce small areas of hair loss, while others affect large areas of the scalp. Common causes of patchy hair loss are
- alopecia areata (small circular or coin size patches of scalp baldness that usually grow back within months),
- traction alopecia (thinning from tight braids or ponytails),
- trichotillomania (the habit of twisting or pulling hair out),
- and tinea capitis (fungal infection).