Alopecia areata

Commonly referred to as male pattern baldness (androgenic alopecia), Alopecia areata is the leading cause of baldness in men. Male-pattern baldness happens because of a gene that converts large quantities of testosterone into DHT (dihydrotestosterone). The DHT hormone damages the hair follicles. The normal life of a hair follicle is 5 years, 4 years for growing, during the fifth year the hair follicle remains inactive.

But in cases were the DHT is imbalanced, the hair follicles get damaged and fallout but are not replaced by new follicles. This is why male pattern baldness occurs gradually. It is irreversible in its later stages. You can observe different kinds of male baldness:

• Male pattern baldness or androgenic alopecia
  
• Loss of some hair from the head known as alopecia areata
  
• Complete loss of hair in the head known as alopecia totalis or Alopecia capitis totalis
  
• Complete loss of hair from the head and the body or alopecia universalis
  

Pattern baldness varies from person to person and depends on the genetic background too. Other common causes for baldness include iron deficiency, wrong treating of hair, chemotherapy, radiation to the scalp, stress and hypothyroidism. Pattern baldness in women occurs during and after pregnancy as also during menopause.