Alopecia areata is an autoimmune condition that causes hair loss on the scalp and elsewhere on the body. It occurs when the immune system mistakenly attacks hair follicles, causing hair to fall out in round patches. Alopecia areata affects both men and women and can occur at any age.

Female pattern hair loss, also known as androgenetic alopecia, is the female counterpart of the more widely recognized male pattern hair loss. Unlike men who present with a receding hairline and hair loss on the top and front, female pattern hair loss presents with widening of the part line which can progress to generalized thinning.

Male-patterned baldness or androgenetic alopecia is the most common form of hair loss affecting men. The condition can start as early as late teens or early twenties, but typically is more common in older men. By 50 years of age, approximately 50% of white men will have some degree of male pattern hair loss.

Scarring hair loss, also known as cicatricial alopecia, is a type of hair loss that occurs when hair follicles are permanently destroyed and replaced by scar tissue. Unlike androgenetic alopecia, which is caused by genetics and hormones, scarring hair loss is caused by underlying medical conditions or physical damage to the hair follicles.

Telogen effluvium is a type of hair loss that occurs when a large number of hair follicles suddenly enter the telogen (resting) phase of the hair growth cycle. Normally, about 10% of the hair on a person's scalp is in the telogen phase at any given time, but in telogen effluvium, this number can increase to 30-35%, leading to excessive hair shedding.

Traction alopecia is a type of hair loss that occurs as a result of the hair being pulled too tightly. It commonly occurs in hair styles such as ponytails, buns, tight braids, cornrows, hair weaves, and hair extensions.