Why Our Nails Are Constantly Growing

Nails are claw-like plates on the tips of the fingers and toes in humans and most primates. They are made of a tough protective protein called alpha-keratin, which is a polymer.

5-Minute Crafts is going to tell you what we need nails for, how fast they regenerate and why they grow all the time.

When human nails start growing

The nail beds (the cell layers under the nails of fingers and toes) start forming in a fetus around the 11th week of pregnancy. Soon after that, the nails start growing — around the 12th week. And by the 20th week, you can already see them clearly on their hands and feet. At this time, they are soft, semi-transparent, and look more like skin rather than the nails we are used to.

During the 3rd trimester of pregnancy, the nails become thicker and solidify. But when a child is born, they are still quite soft and flexible compared to the nails of more adult people.

What we need nails for

Nails have a few useful functions.

• Protection. Nails are protective plates to prevent cuts and scratches on the toes and fingers during our everyday activities.
• Sensation enhancement. The fingers and toes contain nerve endings. They allow the body to process the information it gets every time the fingers touch something. The nail is the opposing force, so when the finger touches things, the nails make the sensitivity stronger.
• Functioning. The nails are the flat versions of claws that help people dig, climb, scratch, grab, and do many other things. Maybe we don’t use all the abilities the nails give us, but our ancestors probably relied on them for survival. Finally, nails work like a tool when you need to grab something very accurately — for example, get a splinter out of the finger, peel an orange, or pick something very small up, like a needle.
• Balance. Toenails also exert counter-pressure on our toes to help us keep balance when walking. The loss of toenails may lead to walking problems.

How fast nails grow

The nails on our fingers grow around 0.14 in a month, and on the toes, it’s much slower — 0.063 in a month, on average. Fingernails need around 3-6 months to fully grow, and toenails need around 12-18 months. The actual growth speed depends on age, sex, season, physical activity, diet, and genetics.

Why our nails are constantly growing

Our nails are constantly growing to ensure protection for our fingers throughout their entire life. If a nail is damaged, or completely peeled off, it’s not something you lose forever. It will grow back and protect the finger.

A constantly growing nail is good because most injuries are not fatal. After a relatively short regeneration period, the fingers will be fully protected again, and such regeneration is repeatable.

Another way of appreciating the importance of nail growth is to understand that our bodies have stuck with this adaptation, despite the cost: nails need nutrients all the time, and they could be used by other body parts. The fact that humans have been growing nails constantly for thousands of years means that the pros outweigh the cons.