I have white hair growth all over my head about 20% and im 21 years old?

What's your question: We don't control hair color, texture, distribution etc. Some lose Not everyone goes bald but some do much earlier than others. Not everyone develops white hair but some do earlier than others. Same goes for distribution, etc. While stress might temporarily lead to hair loss, it won't be a permanent issue. Change in hair color tends to be permanent. Very few metabolic issues affect hair like diabet

Early graying: whitenting of hair is related to genetic predisposition. Age of initial graying is largely a matter of genetics. However stressors: nutritional deficiencies, chemotherapy, traumatic head injuries, low vitamin B levels, zinc deficiency, severe illness, surgery & marked emotional stress may impact earlier depigmentation in people who are already predisposed to gray hair.