Alopecia or hair loss is the medical description of the loss of hair from the head or body, sometimes to the extent of baldness. Unlike the common cosmetic depilation of body hair, alopecia tends to be involuntary and unwelcome, e.g., androgenic alopecia. However, it may also be caused by a psychological compulsion to pull out one's own hair (trichotillomania) or the unforeseen consequences of voluntary hairstyling routines (mechanical "traction alopecia" from excessively tight ponytails or braids, or burns to the scalp from caustic hair relaxer solutions or hot hair irons).

In some cases, alopecia is an indication of an underlying medical concern, such as iron deficiency.

When hair loss occurs in only one section, it is known as alopecia areata. Alopecia universalis is when complete hair loss on the body occurs, similar to how hair loss associated with chemotherapy sometimes affects the entire body.

Causes

• Male pattern baldness
• Androgenetic alopecia
• Fungal infection such as "black dot" tinea or tinea capitis
• Chemical breakage such as over processing, or frequent use of chemical relaxer
• Heat damage as from repeated hot comb use
• Chronic exposure to traction on hair shaft such as "traction" alopecia
• Compulsive hair pulling such as trichotillomania
• Hypothyroidism
• Iron deficiency
• Alopecia areata
• Telogen effluvium resulting from physical or psychological stress
• Hereditary disorder of the hair shaft or genodermatoses
• Secondary syphillis can cause "moth eaten hairloss"
• Discoid lupus erythematosus or chronic cutanous lupus erythematosus
• Lichenplanopilaris
• Pseudopelade of Brocq
• Tufted folliculitis
• Dissecting cellulitis
• Alopecia mucinosa
• Keratosis follicularis spinulosa decalvans
• Adverse effect from certain drugs such as chemotherapy
• Testosterone booster tablets.

External links

• DMOZ: Hair loss