There are different types of hair loss, they are:
1) Androgenetic Alopecia:
Androgenetic Alopecia is one of the causes of hair loss in both males and females. Mostly this is known as male or female pattern baldness and this kind of hair loss occurs due to dihydrotestosterone, which attacks the follicles of hair, that leads to hair loss.
2) Alopecia Areata:
Alopecia Areata is another kind of hair loss that involves the shedding of hair in small patches on the scalp or other parts of the body. This form of alopecia is thought to be caused when the immune system strikes the hair follicles. Actually, we do not know why the immune system strikes the hair follicles in this way but it could be triggered by stress.
Alopecia areata normally results in small sections of hair falling, which may not re-grow for some months. Sometimes the hair does not come back with the same pigments. It is not uncommon for the hair to come back. In unusual situations, the alopecia impacts on the whole of the scalp. In some situations, people who have this type of hair loss will not have re-growth of hair due to a genealogy of alopecia areata or the person has an auto-immune disorder.These problems can be overcome through hair transplantation.
3) Traction Alopecia:
Traction alopecia happens when extreme stress is put on the hair shafts, usually through tying or braiding. Extended traction of the hair can lead to long lasting damage, with the hair declining to re-grow.
4) Telogen Effluvium:
Telogen effluvium explains about the short-term loss of the hair on the scalp. It is not known what causes Telogen effluvium but it is probably brought on by more hairs being in the losing aspect of the pattern than the increasing pattern. Telogen effluvium is therefore short-term, as the hairs will normally re-grow.
5) Alopecia Totalis:
Alopecia Totalis is seen when an individual loses all the hair on his or her head. It is not obvious what causes this but it is believed that it could be activated by an auto-immune problem or pressure.