In men more rarely than in women, hair loss may be due to conditions other than androgenetic alopecia. Some of the most common of these causes are:

Compulsive hair pulling (Trichotillomania)

Hair loss due to trichotillomania is commonly seen in patients who braid or knot there hair. It is  typically patchy, as compulsive hair pullers tend to concentrate the pulling in selected areas. These areas can be easily transplanted

Alopecia areata

a possible autoimmune disorder that causes patchy hair loss that can range from diffuse thinning to extensive areas of baldness with "islands" of retained hair. It is most common in young adults both male and female. 80% of people with Alopecia will eventually regrow all if not most of their hair .  Medical examination is necessary to establish a diagnosis.

Triangular alopecia

Loss of hair in the temporal areas that sometimes begins in childhood. Hair loss may be complete, or a few fine, thin-diameter hairs may remain. The cause of triangular alopecia is not known, but the condition can be treated medically or surgically.

Loose-anagen syndrome

a condition occurring primarily in fair-haired persons in which scalp hair sits loosely in hair follicles and is easily extracted by combing or pulling. The condition may appear in childhood, and may improve as the person ages.