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What Causes Grey Hair? | 6 Common Causes in 2024

Growing up, many of us heard one (or both) of our parents exclaim that our childish antics were giving them grey hair. You may have believed it then, but now that you’re older, you may be wondering yourself what causes grey hair. 

While many people attribute greying hair to old age, there are a number of factors that can play into premature grey hair. We’ll get into those details and more in the following sections. 

What Exactly Is Grey Hair?

Image for a piece on what causes grey hair featuring a woman holding her bangs and looking at herself in the mirror


Grey hair is probably one of the most common beauty problems the world faces. In fact, many dermatologists say that 50 percent of the population has 50 percent grey hair by the age of 50. This phenomenon is known as the 50-50-50 rule. 

However, one study concluded that these numbers were actually far lower than real-life statistics. It showed that 74 percent of people between 45 and 65 years old were affected by grey hair.

To say the least, talking about grey hair matters because it affects so many people. And if you’re dealing with grey hair, you most certainly are not alone. 

But it’s important to understand that greying hair and thinning hair are separate issues. While your hair stem cells create your hair, it’s the pigment-forming cells that produce its color. All this to say that your hair isn’t turning grey; it’s actually growing in grey. 

A Quick Look

There are many different factors that play into getting grey hair. Before we dive in, let’s take a quick look at what we’ll be covering: 

  • Grey hair is most commonly caused by aging and genetics.
  • Some grey hair could be an indicator of a more serious health problem. 
  • Research shows that grey hair may be reversible. 

If you’re interested in learning more, continue reading below. 

What Causes Grey Hair?

Some people begin to notice grey hairs in their 40s and have a full head of silver by their 60s. Other folks start to see greys as early as their 20s. 

But why does this happen? We can certainly blame age in many circumstances, but clearly, that can’t be the only cause. 

In fact, there are several other causes for grey hair that we can explore.

1. Aging

Image of a woman aging with a defined cheekbone structure for an explanation about what causes grey hair


The first and most common cause of grey hair is aging. As we get older, we notice a lot of things changing in our bodies. You may notice a general lack of energy, wrinkled skin, and aching joints. That’s simply because our bodies were not designed to last forever.

Your hair gets its color from a pigment called melanin, which is produced by your hair follicles. The older you get, the less melanin your follicles produce. 

However, your hair keeps growing. 

Rather than your hair turning grey, it just begins to grow in with less or no pigment – resulting in its colorless version: grey. 

2. Genetics

To help explain what causes grey hair, a DNA helix with a piece broken apart in white color with a blurry background

Anusorn Nakdee/Shutterstock

Much of how our hair looks and behaves is determined by one thing that we simply cannot control: genetics. If you’re experiencing premature greying and your doctor hasn’t discovered any underlying causes, you may just have your family bloodline to thank for that.

One specific gene, the IRF4 gene, determines the age at which hair starts to turn grey. A particular variant of this gene is known to cause early greying because it controls how the TYR gene acts. The TYR gene encodes an enzyme that is necessary for melanin production. 

When this variant impacts this particular gene, it’s possible that melanin production is negatively affected. 

And while we’re at it, you can thank genetics for any early signs of hair loss as well. 

3. Nutrient Deficiencies

A bunch of foods with lots of nutrients in them for a piece on what causes grey hair


Nutrient deficiencies can be the cause behind many common problems in the human body, such as hair loss, brittle nails, bleeding gums, and poor vision. But a nutrient deficiency could also be behind your prematurely grey hair. 

If your hair is coming in grey, you may be deficient in one of the following: 

  • Folic Acid
  • Biotin
  • Vitamin B12
  • Vitamin D
  • Iron
  • Selenium

A deficiency in the above nutrients has been associated with greying hair in both children and adults, so it’s worth looking into. 

4. Smoking

Man smoking outside a black marble building to illustrate what causes grey hair

Just Dance/Shutterstock

While there isn’t enough research to fully back the idea that smoking directly causes grey hair, the habit could have some indirect impacts on the situation. 

In general, smoking adds unnecessary stress to the body that can lead to a host of problems. The chemical dependency that comes with a smoking addiction can heavily contribute to premature aging. 

As we’ve already noted, aging is the number one cause of grey hair. So, it’s possible that premature aging from smoking can eventually lead to the greying of your hair.

One study even showed that there may be a significant relationship between the appearance of grey hair before the age of 30 and smoking. If you’re a regular smoker and you’re experiencing premature greying, your smoking could be playing a significant role. 

5. Thyroid Problems

Woman holding her thyroid on the outside of her neck for a piece on factors that cause grey hair

Emily Frost/Shutterstock

Not everyone wants to see grey hairs (although some embrace them), and in some cases, many people don’t even like to acknowledge them. But it’s important to explore all avenues if you think your hair is greying prematurely, as it could be a sign of hypothyroidism

Hypothyroidism is a condition where the thyroid doesn’t make enough of the necessary hormones that your body needs to function. Other signs of this condition include:

  • Fatigue
  • Weight gain
  • Cognitive impairment
  • Sensitivity to cold 

Additionally, many patients diagnosed with hypothyroidism also experience advanced and accelerated hair greying. More women tend to experience hypothyroidism than men, but both can receive the diagnosis. 

6. Vitiligo

Gal with Vitiligo disorder wearing a black spaghetti strap camisole


Vitiligo is a disease that causes the loss of color in the skin and hair. This disease impacts the cells that make melanin, causing them to stop functioning or die altogether.

The result of this disease is patches of discolored areas, usually lighter than the original pigment. For this reason, Vitiligo is most noticeable in individuals with more melanin, which causes them to have naturally darker skin tones. 

While the condition is not physically harmful, life-threatening, or contagious, it does cause individuals impacted by it to feel extremely self-conscious about their appearance. Splotches on the skin can also be accompanied by patches of grey or white hair. 

Frequently Asked Questions

While grey hair is a fairly common occurrence, not many people know a whole lot about it. The comforting part is that you’re not alone. Below, we have some frequently asked questions about grey hair. 

Does stress cause grey hair?

Most scientists agree that stress probably doesn’t cause grey hair, as much as your parents wanted you to believe so. But some experts think that rare cases of severe stress could potentially impact an individual’s health, which may lead to other issues like greying. 

Can I hide grey hair?

Yes. Many people choose to cover their grey hair using semi-permanent or permanent hair dye. If you’re just starting to see grey hairs come through, it’s a good idea to use semi-permanent dye to blend those hairs in with your natural color.

Permanent dyes are helpful for anyone who is seeing about 50 percent grey hair on their head. Permanent colors can completely cover the grey and even look natural. 

However, others choose to embrace their grey hair and let it take over their whole head. This statement is made by many to say that going grey isn’t necessarily a bad thing, and you can still choose to age gracefully. 

Is grey hair at a young age common?

Yes. It is not uncommon for young people between the ages of 25 and 30 to see grey hairs. Premature greying is defined as grey hair occurring before the age of 20 for white individuals, 25 in Asians, and 30 in Africans. 

While premature greying is not as common, it is still widely seen in young people enough that it’s not an oddity. 

Is grey hair reversible?

Some research has indicated that it may be possible to reverse the greying of hairs in younger individuals. While this research is not conclusive, various lifestyle changes and treatments could lead to this reversal:

  • Vitamins (such as biotin and pantothenic)
  • Pharmaceutical drugs
  • Managing stress
  • Quitting smoking
  • Antioxidants

In additional studies, researchers have found that some hairs that previously grew in grey later grew in with color for unknown reasons. You can even develop banding on select hair strands. This occurs when your hair grows in grey in fits and spurts, causing the hair to have bands of grey intermixed with your natural color. More research in the future may be able to give us more solid answers on the topic.

Read Next: Best Vitamins for Hair

So, What Causes Grey Hair?

Woman holding her arms up in a questioning post for a piece on what causes grey hair

Jorge Salmeron/Shutterstock

If you’re 50 years old or older, there’s a very good chance that your grey hair is simply a result of the natural aging process that humans experience. While it may not be your favorite look, it’s super normal and nothing to worry about. 

Younger individuals can also experience grey hair due to conditions and outside factors such as Vitiligo, hypothyroidism, stress, and smoking. 

If you’re experiencing new grey hair growth that you’ve never seen before, it may be very important that you contact your doctor as soon as possible for an exam. 

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