Normally, tiny one-way valves inside each vein keep blood from flowing backward. When valves are damaged or do not work properly, a vein may start to bulge and twist. This is called a varicose vein.
What is going on in the body?
After blood filled with oxygen is pumped through the body, veins bring oxygen-depleted blood back to the heart. Normally, one-way valves inside veins keep gravity from pulling the blood toward the feet. When valves are not normal or have been damaged, blood pools in the vein. The kinks, bulges, and lumps of varicose veins then occur. Varicose veins are most often noticed on the thigh or calf, where they are close enough to the skin to be seen. Varicose veins can, however, occur in other parts of the body.
What are the signs and symptoms of the condition?
Often, varicose veins close to the skin can be seen. They are often described as swollen, enlarged, snakelike, bluish veins that are most noticeable when standing. They are most commonly seen on the back of the calf or inside of the leg from the ankle to the groin. Other symptoms in the legs include: