Why do fingernails grow much faster than toenails?

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Why do fingernails grow much faster than toenails?

In: Biology

You wear shoes. You bonk your feet more regularly than you bonk your hands. Your toenails wear off against your socks and shoes, they wear when you drag them against the ground going from sitting on your legs to standing up. People are generally more careful with their fingers than their toes. But I’m assuming if you work hard labor, your fingernails appear to grow as slow as your toenails.

Nails are basically protective and since our fingers are busier than our toes, they are more likely to need replacing. Also, constant exposure to sun and air may aid their growth. Feet are locked up in shoes most of the time.

Aside from what others have mentioned, your fingers also get much more blood flow than your toes, so they have more nutrients to make nails from

Lots of wrong and anecdotal answers here.

Wearing shoes has nothing to do with it; I’ve been working from home due to the pandemic and hardly ever wear socks anymore, let alone shoes and I’ve only had to clip my toenails a few times. There are also also entire cultures of people who never wear shoes, yet their fingernails still grow faster.

The commenter who said “You bonk your feet more regularly than you bonk your hands.” actually has it completely backwards, because not only do our fingers get exposed to more frequent trauma, but it’s actually that trauma which increases the circulation to our nails. Trauma such as typing away on a keyboard to answer an ELI5 question.

That’s just one theory though, as far as I’m aware no one knows for sure the reason why. The only theories I know of all relate to either circulation or usage, so I’m inclined to believe it’s likely a combination of both:

>There are two plausible theories, though. The first has to do with “terminal trauma,” which, despite how it sounds, has nothing to do with taking the airport shuttle. It essentially means that the more you use a digit, the quicker the nail grows: Your body assumes your fingernails are being worn down by the constant use of your fingers — scratching, typing, picking your nose — so it calls for speedier growth to make up the difference. Meanwhile, your toenails are safe and sound in the comfort of your shoes.

>The second theory suggests that the rate of nail growth corresponds directly with the amount of blood flowing through the digit. Since your hands are closer to the heart than your feet are, more blood is flowing through your fingers than through your toes. Thus, longer fingernails. These theorists also point out that nails in general grow slower in cold weather, when blood flow would be restricted.

>Increased forces on a nail bed also likely change the rate of nail growth. The rate of growth on the nails of an individual’s nondominant hand is slower than the rate on the dominant hand, which is subject to more trauma [6]. Similarly, it has been noted that onchycophagia, a habit commonly known as nail biting and observed even in chimpanzees, increases the rate of nail growth [1,11]. Trauma may lead to increased blood and nutrient supply to the affected area, resulting in increased growth.

I would be curious to know if they’ve done any studies with amputees who use their feet for everything, to see if their toenails grow a similar rate to the average person’s fingernails.