Alopecia areata refers to an auto-immune condition that results in unexpected hair fall (or hair loss). Though this is not a common problem but it affects a large population. In people suffering from alopecia areata, hair fall in chunks can be noticed, often the size of a small coin. In extreme cases, hair fall can be very severe resulting in no hair on scalp or anywhere (scalp, body, eye brows, nostrils etc) on the body.