What Causes White Hair?

Hair becomes white when the follicles stop producing melanin, the pigment responsible for hair color. If your hair is losing pigment earlier than expected, the cause could be hereditary or related to an underlying medical issue.

Changes in hair are common as people age. Perhaps in your youth your hair was a solid shade of brown, black, red, or blonde. As time passes, you might notice thinning in spots or a shift from your original hue to gray or white.

White strands show up more against darker hair tones. Although whitened hair is typically associated with aging, depigmented hairs can appear at any stage of life, even during teenage years or college.

Hair turns white when your body ceases melanin production. Melanin is the pigment that gives hair its color.

In some instances, it is possible to restore pigmentation, but that depends on the underlying reason. Below are six frequent causes of premature white hair.

1. Genetics

Your genes strongly influence when (or whether) your hair will go white. If you notice early white hairs, there’s a good chance a parent or grandparent experienced premature graying as well.

You can’t alter your genetics. If you dislike the appearance of gray hair, hair dye is an available option.

2. Stress

Stress is something everyone faces at times. Prolonged stress can lead to issues such as:

• sleep disturbances
• heightened anxiety
• appetite changes
• elevated blood pressure

Stress can also impact hair. Research has shown that chronic stress may trigger premature graying by affecting the stem cells that replenish pigment in hair.

This may help explain why some leaders or high-profile individuals seem to age or gray more quickly while in demanding roles.

3. Autoimmune disease

An autoimmune condition can be a factor in early white hair. In these disorders, the immune system mistakenly attacks the body’s own cells. In conditions like alopecia or vitiligo, the immune response can target hair and reduce its pigment.

4. Thyroid disorder

Hormonal imbalances from thyroid problems — both hyperthyroidism and hypothyroidism — may contribute to premature whitening of hair.

The thyroid is a butterfly-shaped gland at the base of the neck that helps regulate many bodily functions, including metabolism.

When thyroid function is abnormal, it can affect melanin production and consequently alter hair color.

5. Vitamin B-12 deficiency

Early white hair can also be a sign of insufficient vitamin B-12. This nutrient is crucial for energy and supports healthy hair growth and pigmentation.

A lack of vitamin B-12 is linked to pernicious anemia, a condition in which the body cannot properly absorb the vitamin.

Vitamin B-12 is necessary for producing healthy red blood cells that deliver oxygen to tissues, including hair. A deficiency can weaken hair cells and impair melanin synthesis.

6. Smoking

Smoking has been associated with premature whitening. An early 2013 study reported a relationship between smoking and the onset of gray hair before age 30.

A later 2024 study also identified links between tobacco use and gray hair.

While smoking is well-known to raise the risk of lung cancer and cardiovascular disease, its long-term effects extend beyond those organs and can damage hair. Smoking narrows blood vessels, which can reduce blood supply to hair follicles and increase hair loss. The toxins in cigarettes can harm hair follicles and contribute to early whitening.

Frequently asked questions about white hair

Can white hair be prevented?

White hair is a normal aspect of aging and cannot always be avoided. However, if whitening is caused by a treatable condition, addressing that issue may slow or halt further white hair development.

For instance, correcting a vitamin B-12 deficiency or treating a thyroid disorder might boost melanin production in hair follicles and reduce new white growth.

The American Academy of Dermatology suggests strategies that may help slow graying:

• maintain a healthy lifestyle
• eat a nutritious, balanced diet
• get adequate sleep
• avoid smoking
• manage stress
• shield skin and hair from UV exposure

What’s the average age for hair to turn white?

Several factors influence when white hairs appear, including:

• genetics (when your relatives started graying is often predictive)
• ethnicity
• chronic stress
• nutritional shortfalls

Generally, many people will have a significant amount of white hair by age 50.

What causes white hair at a young age?

In younger individuals (teens and those in their 20s), a common cause of early white hair is nutrient deficiency. Low levels of iron, vitamin B-12, or vitamin D-3 can diminish melanin production in follicles, leading to unpigmented or white hairs.

Takeaway

The main factors behind white hair include aging, heredity, stress, vitamin deficiencies, smoking, and medical conditions.

Whether white hair can be reversed or prevented depends on the root cause. If genetics are responsible, there’s no permanent way to stop or reverse the change in color.

If you suspect a medical issue, see a healthcare professional to determine whether an underlying condition is causing the whitening. Treating that condition may restore some pigmentation, but results are not guaranteed.