Male pattern hair loss (MPHL) is the most common type of hair loss in men. About 50% of men are affected by it at the age 50, and the frequency and severity increase with age. It is believed to be related to a combined effect of genetics and hormone dihydrotestosterone (DHT).
MPHL is characterized by thinning of hair and progressive loss of hair on the scalp in a characteristic pattern. The front of the scalp, sides of the scalp, and crown of the scalp are typical sites of involvement. Back of the scalp is spared.
Female pattern hair loss (FPHL) is a common form of non-scarring hair loss that most frequently occurs in adult women. It primarily affects the frontal scalp and vertex of the scalp. If left untreated, FPHL will result in a slow, progressive decline in the density of scalp hair. Fortunately, complete baldness is very unlikely.
Any physical stress such as major surgery, accident or even serious illness could cause temporary loss of hair.
Thyroid disease, anemia, chemotherapy, protein deficiency and low vitamin levels may lead to hair loss.
Skin condition of the scalp such as seborrheic dermatitis, psoriasis and fungal infection like ringworm could also cause hair loss.
Alopecia areata is a form of hair loss initiated the autoimmune destruction of hair follicles in localized areas of skin.