Varicose veins are enlarged "rope-like" veins — blood vessels — that are swollen and raised above the surface of the skin. They can be flesh-colored, dark purple, or blue, and often look like a cluster of grapes. They are commonly found on the back of the calves or the inside of the legs. However, they can form anywhere on the legs, from groin to ankle.

Spider veins are similar to varicose veins, but they are smaller and closer to the surface of the skin. They are often red or blue, and look like tree branches or spider webs. They can occur anywhere on the legs, and can cover either a very small or very large area of skin. They don't bulge like varicose veins, but are often more noticeable.

Common risk factors for varicose and spider veins include:

• Increasing age
• Family history
• Pregnancy and hormonal changes
• Obesity
• Prolonged standing
• Prior deep venous thrombosis

Spider veins are often found on the legs or face, and look like red, blue or purple spider webs just under the skin. They do not make the skin bulge like varicose veins do.

Spider veins can affect anyone, but are most commonly found in women. The causes of spider veins vary from person to person, so if you get spider veins it is important to see a specialist to find out what caused them.

Sclerotherapy is an injection procedure to treat spider veins and small varicose veins. The procedure involves injection of a sterile solution (called a sclerosing solution) into the small veins using a very fine needle. This solution irritates the vein lining causing it to undergo fibrosis and eventually disappear. Many veins are injected at each session.