We normally just equate grey hairs with...well, with getting old.

But whether those pesky hairs come about later in life or earlier, they're telling us far more than we realize about our bodies and our health. See what else a grey hair can mean with the fascinating explanations below.

Grey hairs come about as a result of a lack of pigment.

The older we get, the less pigment we produce, the less hair we have. Simple enough, right?

There's a pretty simple breakdown of how people develop grey hairs over time.

Dermatologists say that by age fifty, 50% of the population has 50% grey hair.

There are exceptions based on demographics, though.

via: Jamaica Hospital

White people tend to get grey hairs in their mid-30s. Asians in their late-30s, and Black people in their mid-40s. If you're developing grey hairs well before that, there could be a deeper reason.

Those who go grey early often have lower levels of D3 and B12 vitamins.

Grey hair has also been linked to heart disease.

via: Health Nation

The men who experienced coronary heart disease have been found to have whiter hair than those who don't.

So what do grey hair and heart disease have in common?

via: Telugu Roommate

Well, a recent hypothesis says that the two phenomena share molecular structures and also hormone changes or imbalances.

Sometimes, it's just genetic.

via: NE Psychiatric

If your relatives went grey early, there's a good chance you will too.

An Indian dermatology journal found that smokers were a staggering 2.5X more likely to develop grey hair than nonsmokers.

via: South Asian Daily

Smoke's chemicals break down hair cells and can also lead to balding and hair loss.

via: Organic Facts

Another factor could be oxidative stress. That's an imbalance in free radicals, often caused by pollution or an unhealthy diet.

via: Organic Facts

The stress can cause your hair follicles to produce hydrogen peroxide, which leads to greyer hair.

via: Living Healthcare

Another journal found that people who went grey for seemingly no other reasons were 4X likelier to have or develop osteopenia.

via: Babble

That's a condition that, if left untreated, can lead to osteoporosis, which in turn can lead to broken and weak bones.

via: FAIM

If your hair's grey, thinning, or fine, that could be a symptom that your thyroid isn't functioning properly.

via: Ottawa Osteopath

Eastern medicine suggests that the quality of your blood and the health of your kidneys are reflected in your hair. The greyer your hair is, the worse off those are.

via: Emedicine Health

So think about all the proper causes. If you can't find any after consulting a doctor, it's likely just time for you to go grey!

via: The Daily Quotes