You are young to have gray hair, but it happens.  And usually, there’s not much you can do about it.

Hair turns gray when cells (called melanocytes) in hair follicles stop producing melanin. This is the pigment that gives hair its color.  A gray hair has reduced melanin. A white hair grows out when these cells stop producing melanin altogether.

For most, this begins after age 35.  But the age at which hair starts to turn gray varies widely.  Perfectly healthy people can start to turn gray well before age 35.  Others make into advanced age without turning gray at all.

In addition to age, there are a number of factors that contribute to the age at which hair becomes gray. These include:

• Heredity. Premature graying is common in some families.
• Gender. Men tend to get gray hair at an earlier age than women.
• Certain diseases. Examples include vitamin B12 deficiency, thyroid disease and vitiligo (an autoimmune skin disease).  Skin conditions, such as eczema or scalp infections, may also cause graying. And these causes may be reversible once the skin disease is treated.
• Smoking. Those who smoke are more likely to turn gray at a young age.
• Medications. Certain drugs, such as lithium and methotrexate, can cause hair to fall out, making the remaining gray hair more noticeable.

A common misconception is that stress turns hair gray. There are rare examples of people suddenly losing pigmented (darker) hair, which makes their gray hair more noticeable. But everyday stress or worry does not change hair color.

Researchers are looking for ways to restore the capacity of melanocytes to produce melanin after hair turns gray.  Until then, there are only a few ways to handle the situation: color your hair, shave your head or do nothing. I recommend a checkup with your doctor to make sure you are in good health and to look for reversible causes of premature graying.  Most of the time there is no disease, condition or other identifiable reason for premature graying. And unfortunately, no way to stop the process.