Key Difference: Greying is an illusion created by white hairs mixed with the black hairs creating a ‘salt and pepper’ or ‘greying’ look. Grey and white hairs are one and the same, just different terms.

Grey hair is a misconception, as grey hair does not exist. The grey hair is considered as an optical illusion caused by white hairs mixing with the black hairs, creating a greying look. Let’s back up a bit and see about hair color in detail.

The color of hair happens at the follicle and the hair receives it color from two pigments in the hair shaft, eumelanin and phomelanin. The eumelanin determines how dark hair will be; the more eumelanin, the darker the hair. Phomelanin makes the hair redder. All hair colors are a combination of these pigments. The mixes of the pigments are decided by your genetics, which is why a red haired child, must have a red haired parent.

As a person ages, the hair follicles stop making the pigments causing the hair to turn white. This term is known as achromotrichia and the rate at which each hair follicle stops producing the pigment differs, causing the hair to turn white one at a time. The pigment producing cells in the follicle die and is not replaced.

So how do young people have white hair? Achromotrichia can occur at any age; it is not definite and differs from person to person.  Some people can get white hair as early as in their twenties, while some don’t get their first white hair until late forties. In some cases, white hair can also be caused by thyroid deficiencies, Waardenburg syndrome or a vitamin B12 deficiency.

According to BBC news, research shows that the anti-cancer drug Imatinib can reverse the process of ‘greying’ hair, but it is expensive and has deadly side-effects. But if mechanism of action of Imatinib can be discovered, there may be a safer and less expensive option for reversing white hair somewhere in the future.