Many people consider their hair -- and hair color -- one of their greatest beauty assets. So while losing your normal color, as hair turns gray, white or silver, is an expected part of aging, premature graying is not such a welcome change. The most common cause of white, gray or silver hair is thought to be genetics, but sometimes this change is related to a medical issue that requires evaluation and treatment.
How Hair Loses Color
Melanin gives hair its color, whether the hue is black, red, blonde, brown -- or any shade in between. This pigment, which is found in hair follicles, or the sheath of cells and tissue that surround the hair root, is an ingredient in the hair formation process. Over time, less melanin is available during hair growth, and this loss of pigment causes the hair to turn gray, silver and eventually white. Gray or silver hair is either caused by low levels of pigment, or is an illusion created by the mix of white and dark hair on the scalp. White hair is related to a complete loss of pigment.
Premature graying is defined as loss of hair pigment that occurs before the age of 20 in Caucasians, before the age of 25 in Asians, and before the age of 30 in Africans, according to a June 2017 review in "Pigment International." Although the underlying mechanisms are still not clearly defined, the most common explanation for the premature whitening or graying of hair is genetics. For example, your genes can lead to defects in the cells that produce melanin, or stop this melanin production at an early age.
Certain autoimmune disorders can cause the hair to whiten, or may create the illusion of whitened hair. Case reports have determined the hair that regrows after the scalp is affected by alopecia areata, a condition which causes round patches of hair loss, can be depigmented, or white. Alopecia totalis, a form of alopecia areata that leads to total loss of hair on the scalp, can sometimes selectively affect pigmented hair -- leaving only the white hair in place. Vitiligo is another autoimmune disorder which causes the pigment-making cells to be destroyed. While this condition often affects the skin, it can also lead to patches of white hair.
Premature graying is less commonly linked to other medical conditions. According to an August 2013 review, thyroid disorders, early aging syndromes or medication side effects can cause loss of hair pigment. Deficiencies of vitamin B12, copper, as well as severe malnutrition have been linked to premature graying or loss of hair pigment, which may be reversible. Iron, folic acid and vitamin D3 also play a role in pigmentation of hair, and the role of these nutrients in early color loss is being investigated. Smoking is another potential cause of premature graying of hair. Stress has long been thought to be a cause of sudden or early hair whitening, but loss of color does not occur in existing hair strands. Severe stress is more likely to cause excessive shedding of hair, according to the American Academy of Dermatology.
Precautions and Next Steps
Premature graying or whitening of hair is usually blamed on genetics, and often is not related to a medical condition. Because white, silver and even gray hair colors are becoming more trendy and stylish, many people choose to embrace their hair color changes. However, coloring or dyeing your hair is an option is you aren't ready to go white or gray. If you are graying prematurely, and it doesn't run in your family, or if you have a sudden change in hair color or excessive hair loss, discuss your symptoms and concerns your doctor.
Reviewed by Kay Peck, MPH RD
Is This an Emergency?
- Indian Journal of Dermatology, Venerology and Leprology: Premature Graying of Hair
- American Academy of Dermatology: Vitiligo
- Pigment International: Biology of Hair Pigmentation and Its Role in Premature Canities
- Journal of the Royal Society of Medicine: Sudden Whitening of the Hair: An Historical Fiction?
- Dermatology and Dermatologic Diseases: Overnight Graying? Phenomenon: A Case of Widespread Non-Pigmented Hair Regrowth in Diffuse Alopecia Areata
- University of Michigan Health System: Hypothyroidism