Cause of<unk>  is incompletely understood. It is a complex multi-factorial process mainly considered to be an interplay of nutritional, genetic and environmental factors. Stress causing over-activation of the sympathetic nervous system increases noradrenaline release in hair follicles. This overproduction causes depletion of the melanocyte stem cells which are required to produce melanin, the pigment responsible for hair color. Nutritional deficiencies like vitamin B12 deficiency, severe iron deficiency, chronic protein loss, copper deficiency are often found associated with<unk> s. Other factors that have been incriminated are low serum ferritin, and low serum calcium and vitamin D3 levels.<unk>  has been observed with greater frequency among certain families, suggesting a familial predisposition for the condition. As hair pigmentation is a result of complex interaction between various genetic factors, it is thought that<unk><unk>  could be due to exhaustion of melanocyte's capability to produce hair pigmentation.<unk>  canities may occur alone as an autosomal dominant condition or in association with various autoimmune or<unk>  aging syndromes. Down syndrome (trisomy 21) is characterized by features of accelerated aging including<unk>  and deficient DNA repair.<unk><unk>  needs to be differentiated from various genetic hypomelanotic hair disorders. Smoking is another factor that is considered to be related to<unk> . Smoking results in generation of huge amount of reactive oxygen species leading to increased oxidative stress culminating into damage to melanin producing cells, melanocytes. Prolonged exposure to ultraviolet rays is considered to initiate similar processes in hair follicles resulting in<unk> .
Premature greying of hair
Scarring hair loss
Auricular hypertrichosis
Prepubertal hypertrichosis
Non scarring hair loss
Pattern hair loss
Oral galvanism
Focal facial dermal dysplasia