Why are veins popping out of my legs?

Venous insufficinecy: Visible veins on the legs are the result of venous insufficiency. The insufficiency may be in the skin [resulting tiny spider veins], or below the surface of the skin [ causing tiny and varicose veins] or in deep veins. It is best to have this evaluated by a vein specialist, often with aid of an ultrasound to see how best to treat. Now treatments are simpler and more effective than ever.

Heredity: Heredity is the reason that you get varicose veins but, as dr. Wright said, the problem is that there are valves in the underlying veins in your legs that are failing. This causes blood to flow backwards (reflux) in these veins. We call this venous insufficiency. Reflux causes venous hypertension and results in veins popping out of your legs. You should see a vein specialist.