Saturday, October 22, 2011

Various Types of Hair Loss

Normal human hair grows in a cycle consists of 2 phases: growth phase and rest phase.

In growth phase (anagen) which lasts for 2-3 years, the hair grow about 1cm a month. After that, it enters rest phase (telogen) which lasts for 3-4 months. During rest phase, hairs stop to grow. At the end of rest phase, the hairs will fall and a new cycle of growth phase will begin. A person normally shed 50-100 hairs a day.

Causes of hair loss:
  • aging
    • 40% of men by 35 years old and 65% of men by 60 years old have noticeable hair loss
    • 50% of women by 50 years old have noticeable hair loss
  • genetic 
    • more prone to develop hair loss if one of your immediate family has it
  • poor nutrition
    • iron, zinc or protein deficiency
  • medication
    • warfarin, fibrates, anti-acne, ACE-inhibitor, calcium-channels blockers, allopurinol, anti-thyroid drugs, epilepsy drugs, birth control pills etc
  • male-pattern baldness (androgenic alopecia)
    • hair loss at both temporal areas & the top
    • treated with oral finasteride / topical minoxidil

  • female-pattern baldness (androgenetic)
    • hair thinning at the mid-line top
    • treated with oral anti-androgen / topical minoxidil

  • telogen effluvium 
    • hair growth enters into telogen phase prematurely, triggered by body insult / stress such as: emotional/physical stress, surgery, starvation, high fever, serious illness, extreme diets, childbirth etc
    • hair loss starts 3-4 months after the stress event
    • reversible after the stress factors subside

  • anagen effluvium
    • caused by chemotherapy drugs where actively growing hairs at anagen phase are most affected
  • tinea capitis (scalp fungal infection / ringworm)
    • itchy red scaly scalp with patchy hair loss
    • treated with topical anti-fungal 

  • alopecia areata
    • autoimmune disorder with exact cause unknown
    • non-scarring patchy hair loss
    • may regress (hair grow back), recur or progress to total baldness
    • treated with topical steroids/minoxidil or monthly steroid injection

  • cicatricial alopecia (scarring)
    • caused by inflammation and damage to hair follicles
    • patchy and permanent hair loss
    • associated with SLE and lichen planus

  • traction alopecia
    • caused by regular use of hairstyles that tightly pulling the hair
    • patchy hair loss and non-permanent hair loss
  • hormonal changes
    • hyper- or hypothyroid
    • diabetes
    • childbirth / menopause
  • excessive hair styling
    • chemicals used & over-styling
  • trichotillomania
    • a mental disorder with irresistible hair-pulling
    • patchy bald areas

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