Genetically determined ( reason:Inheritance ) 95%for men and 75% for women
  • Development is related to age and presence of androgenic hormones/receptors
  • Alopecia areata: Although exact etiology is unknown, there is a genetic predisposition, and consensus favors an autoimmune response
  • Telogen effluvium: Normal hair cycle is interrupted so that anagen (growing) hairs are abruptly converted into telogen (resting) hairs, which are subsequently shed after 2 to 4 months
  • Hypothyroidism and hyperthyroidism
  • Postpartum, post-illness
  • Surgery with general anesthesia
  • Nutritional deficiency, particularly with iron or zinc
  • Psychological stress
  • Most telogen effluvium from medications is caused by retinoids, β-blockers, calcium channel blockers, antidepressants, and nonsteroidal anti-inflammatory drugs (including ibuprofen)
  • Tinea capitis: Ringworm of the scalp in which dermatophyte fungus invades the hair shaft. The most likely dermatophytes include
  • Microsporum (from cats and dogs)


  1. Family history of baldness
  2. Advanced age
  3. Physical stress
  4. Psychological stress
  5. Pregnancy
  6. Regular use of aggressive hair-styling techniques
  7. Poor nutrition
  8. Rapid weight loss
  9. Restrictive diets (eg, low carbohydrate, low fat)


Incidence and prevalence:

  • About 25% of men aged 25 years have some degree of clinically apparent androgenic alopecia
  • About 42% of men develop androgenic alopecia
  • About 2% to 3% of the general population develops alopecia areata