Shereene IdrissBoard Certified Derm, Founder and Chief Nerd

Why do your fingers wrinkle in water? — Dermatologist explains the science

29 Jul 2026 · 2 min

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1:49

In this video dermatologist Shereene Idriss explains that the familiar wrinkling of fingertips after immersion in water is not caused by the skin absorbing water, but by an active neurological response. When the fingers are submerged for a few minutes, tiny sensory nerves trigger the sympathetic nervous system to constrict blood vessels in the fingertip pulp. The resulting loss of blood volume causes the overlying skin to collapse, forming ridges and grooves. This response is absent in individuals with certain nerve injuries, demonstrating that the process is nerve‑mediated rather than a passive swelling effect. Idriss argues that the adaptive purpose of this vasoconstriction‑induced wrinkling is to improve grip on wet or slippery objects, much like tire treads, by channeling water away from the contact surface. The phenomenon is limited to hairless, glabrous skin on palms and soles, which are the areas most needed for grasping. The video thus frames fingertip wrinkling as a calculated, evolutionarily advantageous response orchestrated by the brain to enhance handling of wet objects.

Chapters

You have noticed that your fingers wrinkle your whole life, since you were a kid, while in a bath or maybe while swimming outside. And you've probably assumed that your fingers wrinkle because of water, right? Well, I'm a dermatologist. I'm here to tell you it has nothing to do with water. And the reason why your fingers wrinkle is fascinating. Your fingers wrinkle because your brain decides to wrinkle them. You see, if you soak the fingers of somebody who has a specific nerve injury, Nothing happens. They stay smooth no matter how long they're underwater for. And if it was just the water swelling your skin, that wouldn't matter because water doesn't care whether or not you have a nerve injury or not. So it's not the water doing this, it's your nervous system. And here's what's actually happening. When your hands have been underwater for a few minutes, we have tiny nerves in our fingers that signals to the blood vessels to narrow and constrict., and when they shrink, the tissue volume around it starts to deflate. So what do you see on your fingers? You start to notice ridges and grooves in your fingers, and you get wrinkly, and you look old AF on your fingertips. But now the question is, why does that happen? It boils down to grip, just like treads on a tire. These little channels that form squeeze water out of the way so that you can grab something and hold on to it when your hands are slippery. Like, think of your arms. Your arms don't wrinkle, and you can't really hold on to anything if your arm was slippery. So this being wet is signaling to your body that you need to be able to grasp things that are slippery better. And so all of the hairless skin on your body, your palms and your soles, become wrinkled because it is more efficient to pick up something with wrinkled skin versus smooth skin. So no, your fingers are not being waterlogged, but they are making a calculated decision to help you hold on better.