Why Do Our Hands Get Wrinkly in Water?

“Mommy, why do our hands get curly and weird in water?” One fine day, as Han came from his bath, he asked me why our hands got curly (he meant wrinkly).

Hi there! I’m Najma, a content writer by day, mom of two curious kiddos by… well, always! Usually, I write to help businesses connect with their audiences and solve real problems. But this series is a bit of a personal mission.

You see, my four-year-old has hit that magical phase of endless questions. Lately, I’ve decided I’m going to answer almost every single one of his funny, random, and sometimes tricky questions in Medium articles. He may not fully get it now, but maybe one day he’ll know that his mom really did take his questions seriously and had a lot of fun doing it.

So, if you’ve ever wondered why our hands get wrinkly in the bath, why does the fish stick, or why do owls sleep during the day, stick around! I promise plenty of giggles, lightbulb moments, and maybe even a few “Whoa, I didn’t know that either!” moments along the way. Let the adventures begin!

The Science Behind Wrinkly Hands

Something really cool happens when our hands stay in water for more than 5 minutes. The water starts to soak into your skin through little openings called sweat ducts. After a few minutes, nerve fibers in your skin notice this and send a signal to your brain.

Now, your brain tells a special part of your nervous system, called the autonomic nervous system, to do something. This system makes your blood vessels get smaller — a process called digital vasoconstriction. When the blood vessels get narrower, less blood flows through them, and your skin loses some of its volume.

So, as the blood vessels shrink, your skin starts to fold and wrinkle! These wrinkles help you grip things better, especially when they’re wet — like when you’re trying to hold a slippery rock or a fish.

Here are a couple of other things to know:

• It takes a few minutes for your fingers to start wrinkling, and warmer water can make it happen faster.
• Your skin also turns a little paler because the blood vessels are narrower.
• If someone has nerve damage, their blood vessels won’t narrow, so their fingers won’t wrinkle.

So, next time your fingers start to look like prunes in the pool, you’ll know that your body is doing something cool to help you hang onto things better!