You're going about your day when you glance down at your hands and notice them—those blue or greenish lines beneath your skin, suddenly more prominent than you remember. Maybe they've always been there. Maybe they're new. Maybe you're wondering if it means something is wrong.

Let's put your mind at ease: visible hand veins are usually completely normal. In fact, for most people, they're simply a sign of anatomy, age, or temporary physical conditions. But sometimes, they can signal something worth paying attention to.

Here's what your visible hand veins might be telling you.

First, the Good News

Visible hand veins are rarely a cause for concern. They're often a sign of:

Low body fat – Veins lie closer to the surface when there's less fat tissue.
Thin or fair skin – Some people naturally have more translucent skin.
Aging – Skin naturally thins and loses elasticity over time.
Exercise – Working out increases blood flow and temporarily makes veins more prominent.
Heat – Warm temperatures cause veins to dilate (vasodilation) as your body tries to cool itself.
Hydration status – Good hydration can make veins more visible; dehydration makes them less plump.
Genetics – Some families just have more visible veins.