Varicose veins are swollen, twisted veins that you can see just under the skin. They usually occur in the legs, but also can form in other parts of the body. Hemorrhoids are a type of varicose vein.
Spider veins are like varicose veins, but smaller and closer to the surface of the skin. They are often red or blue, and can look like tree branches or spider webs. They are mostly found on a person's legs or face. They may cover a small or large area.
Your veins have one-way valves that help keep blood flowing toward your heart. If the valves are weak or damaged, blood can back up and pool in your veins. This causes the veins to swell, which can lead to varicose veins.
Doctors aren't sure of the exact cause of varicose veins because of the complex nature of veins, the body's blood circulation
system, and other body processes that affect the way veins work.
What's known for sure is that the valves that push blood through the varicose veins stop working properly, causing blood to collect in areas in the veins. The veins then expand and the blood in them begins flowing in reverse. Evidence suggests varicose veins may be veins that are naturally weak, a condition that could be inherited. This could explain why varicose veins seem to run in families.
Varicose veins are very common. You are more at risk if you are older, a female, obese, don't exercise, have a family history or stand for long periods. They can also be more common in pregnancy.