Millions of women are bothered by spider veins — those small yet unsightly clusters of red, blue or purple veins that most commonly appear on the thighs, calves and ankles. In fact, it's estimated that at least half of the adult female population is plagued with this common cosmetic problem.

What causes spider veins?
The cause of spider veins is not completely known. In many cases they seem to run in families. Spider veins appear in both men and women, but more frequently in women. Puberty, birth control pills, pregnancy, or hormone replacement therapy often seem to cause them to surface. They may also appear after a surgery or an injury.

How are unwanted blood vessels on the legs treated?
The injection method, a procedure called sclerotherapy is used to treat unwanted blood vessels. A sclerosing solution, is injected with a very fine needle directly into the blood vessel. This procedure has been used for spider veins since the 1930's and before that for larger veins. The solution irritates the lining of the vessel, causing it to swell, stick together, and the blood to thicken. Over a period of weeks, the vessel turns into scar tissue that is absorbed, eventually becoming barely noticeable or invisible. A single blood vessel may have to be injected more than once, some weeks or months apart, depending on its size. In any one treatment session, a number of vessels can be injected.

How successful is sclerotherapy?
After several treatments, most patients can expect a 50 to 90 percent improvement. However, fading is gradual, usually over months. Disappearance of spider veins is usually achieved, but similar veins may appear in the same general area.

Will insurance cover the treatment of unwanted blood vessels?
Insurance rarely covers treatment of spider veins but may sometimes cover larger vein treatment. If the treatment is solely for cosmetic reasons, it will not be covered by insurance.

Are there side effects to spider vein treatments?

  • Red, raised areas at the sites of injection—These hive-like areas should disappear within a day or so.
  • Brown lines or spots on the skin at the sites of treated blood vessels—these are made up of a form of iron in the blood. These darkened areas may result when blood escapes from treated veins. These areas occur more often in patients who have larger veins treated. In most cases, they disappear within six months to a year, but in a small percentage of patients they may last longer.
  • Development of groups of fine red blood vessels near the sites of the injection of larger vessels, especially on the thighs—About one third of patients develop these and most disappear by themselves. Others may disappear with additional injection treatments or laser therapy, however, a few may be permanent.
  • Bruises at the site where the needle went into the skin—These disappear in a few weeks and are probably related to the thinness of blood vessel walls.
  • Inflammation of treated blood vessels—This is very unusual, but when it occurs, it is treated with medications such as aspirin, compression, antibiotics or heat.
  • Lumps in injected vessels, particularly larger ones, may develop—This is coagulated blood, similar to a bruise with the vein, but is not dangerous.

Is a history of blood clots in the lungs or legs a reason to avoid therapy?
Not necessarily, but the procedure must be done with caution to lessen the risk of blood clots.