Blood returning to the heart from the feet and legs has to flow upwards against gravity. The calf and thigh muscles help to pump blood up and valves in the veins prevent the backward flow towards the feet.
Venous insufficiency, the root of most vein issues, occurs when your veins dilate (widen and stretch) and the valves are unable to close properly. This reduces the ability of the affected veins to return blood to the heart, causing them to bulge.
When the small blood vessels near the surface of your skin dilate, they become visible as tiny red or blue veins on the surface of the skin called spider veins. Some clusters of spider veins can appear like a bruise.
Spider veins are not harmful, and typically form due to hormonal changes, pregnancy, heredity, or injury. However, their appearance can make you self-conscious.
When a vein dilates, and the valves cannot effectively close to prevent the backflow of blood, varicose veins start appearing on the skin surface. Pressure from blood backing up in your veins can cause the veins to bulge and appear twisted or ropy. Your leg may also swell and ache, and feel full, heavy, and fatigued.
Any problems that affect the saphenous veins can interfere with the side veins that drain into them, causing the smaller veins to dilate and become varicose. Varicose veins are larger than spider veins, and are usually associated with changes in skin color, bleeding, and ulcers. In some cases, blood in the varicose vein can clot, causing the wall to become inflamed and result in swelling, redness, or sudden pain in the affected area.
What to Do
If varicose veins or spider veins are causing you to feel self-conscious, you should see your doctor for a proper diagnosis and personalized treatment plan.