Anatomy of the Veins
Arteries bring oxygen-rich blood away from the heart to the extremities, and can be thought of as a tube or hose. Veins, unlike arteries, have one-way valves (like a check-valve or one way door) that help to direct oxygen-depleted blood up the legs towards the heart. In normal veins, the one-way valves close so that blood cannot leak back down the legs. In people with vein disease, the one-way valves don't close all the way. Blood then leaks back down the veins (venous reflux) and collects in the legs, causing the veins to enlarge and causing symptoms or complications.
There are three types of veins in the leg:
- Superficial veins: visible veins within the skin or just below the skin which may include spider veins, varicose veins, and reticular veins.
- Deep veins: the main veins which are located within the leg muscles or in the pelvis and abdomen.
- Perforator veins: connect the superficial and deep veins.
Vein disease may affect any of these three types of vein. Symptoms may be more severe and complications are more likely to develop when disease occurs within more than one type.