I once read a manga about a wife who lost her husband and the agony was to much that it caused her hair to turn silver .... Maybe this is the same ? Just a guess
Yup
There is an autoimmune condition, known as alopecia areata, which can attack hair follicles. This disorder causes pigmented hair to fall out. Follicles that are black, brown, red, or blonde are susceptible to the disease while follicles that produce gray and white non-pigmented hairs are left completely untouched. Because stress is a factor in autoimmune diseases, it can trigger the disorder, making a person appear as if their hair turned completely white overnight.
If a person were to have a rough night, get in a heated argument, or experience a life or death situation, the disease could be triggered. The person would wake up with most of their pigmented hair gone, leaving only the gray or white hair. This would make it look like the person was frightened so bad that their hair turned white.
Because we’ve only recently begun to understand autoimmune diseases, it’s no surprise that the myth has a long history. The first documented case of sudden hair whitening was in the Talmud in 83 A.D. The victim was a 17 year old boy who had been appointed chief of the main Israeli Talmudic academy. His hair turned white virtually overnight. The boy claimed his sudden white hair was “a consequence of strenuous studying.”
Thanks to all of you (I don't know if both of the anonymous replies are from the same person.) for telling me^^
... why did his hair turn white????