Hi
premature greying of hair doesn't always mean it's pathological ,
Heredity factors,Dirty conditions of the scalp
Using electric dryers,Using concentrated hair dyes,Nutritional deficiency,Washing hair with ward water,Anemia,Hormonal imbalance
Illness and infectious diseases,Stress and anxiety,Toxic / heavy metal poisoning,
Vitiligo,
Thyroid disease,Folic acid deficiency.