Two important mechanisms of patterned hair loss ?
1. Androgenic alopecia is caused by the hair follicle miniaturizing effect of Dehydrotestosterone – DHT which is the a hormonal breakdown product of testosterone. Balding individuals do not have an abnormal level of DHT, rather it is their genetic predisposition to having DHT sensitive hair in the balding area that causes hair loss.
2. Genes also create androgenic protein receptors on the hair follicles. Some people will inherit the blue print code for weaker structures which offer poor levels of protection from DHT. This causes the hair follicles to shrink.
It is also important to realize the environmental variables can enhance the effect of genes by increasing the rate of hair loss . Likewise, these hair loss causing environmental factors can also influence the rate of hair shedding and thinning. Examples include Diet, the intake of harmful chemicals (e.g. nicotine and alcohol), pollution and sun exposure are some examples. Medical conditions like thyroid disorders can exacerbate hair loss , particularly in those who are predisposed to pattern baldness.
Hair loss and environmental factors: Does Nature or Nurture Determine hair loss?