Prominent veins in the hands are often harmless and common in young people. “Most of the time, prominent veins in the hands at a young age are a common, harmless variation” caused by factors like low body fat, genetics, or fair skin.

Slim individuals may notice veins more because “the lack of fat cushioning causes veins to look more visible.” Thin or fair skin also makes them stand out, often appearing blue or purple. Genetics plays a role as well—if relatives have visible veins, you likely will too.

Exercise increases blood flow, making veins swell and appear more noticeable, a normal effect called vascularity. Hot weather can also cause veins to dilate as the body cools, while hormonal changes during puberty may temporarily highlight veins.

Usually harmless, visible veins should only raise concern if they appear with other symptoms. “Deep Vein Thrombosis (DVT)…causes swelling and pain in one hand or arm, as well as visible veins,” requiring urgent care. Superficial thrombophlebitis may cause veins to feel hard, tender, or warm.

In rare cases, varicose veins in the hands or connective tissue disorders like Vascular Ehlers-Danlos syndrome may be the cause, especially if accompanied by pain, swelling, or unusually thin skin.