Hair Going White Overnight

Frightened man with gray hair
Photo: Alice Day/Shutterstock
Q: My friend who is a hairstylist was telling me about a condition where your hair can turn white overnight from stress or shock or whatever. I was wondering if this was true and what it is called.
A: Well, according to professionals such as dermatologists and other physicians, there is NO disease or disorder that will cause the hair to go white overnight. Even the legendary reports are suspect in their details. Thomas Moore and Marie Antoinette are reported to have undergone overnight whitening of the hair.
There has been suggestion that the cases of the hair going spontaneously white are a result of a condition called "diffuse alopecia areata". In this form of alopecia, the hair spontaneously thins as random hairs turn loose and are shed. The diffuse alopecia is more likely to affect pigmented hairs as opposed to unpigmented (gray) hairs.
As a result, if an individual had a good mix of evenly dispersed gray and pigmented hair and developed diffuse alopecia areata, the pigmented hair could be shed rapidly, giving the impression of nearly overnight whitening of the hair.
There is a case documented by a French doctor, Dr. Douglas Nelson, of a 45-year-old farmer whose hair went from black to white over a period of 14 days. The hair reportedly stayed white for about six months and began to return to black over a period of 4 months. He was completely healthy, underwent no shock or fright, and there has been no explanation found for his experience.
See also:
Why and how hair turns gray
What is the average age for going gray?
How do you know if your gray hair is premature?
My hair color is going darker instead of gray. Why is this happening?