Spider Veins Sclerotherapy is when veins are injected with one of several types of solutions that irritate the lining and harmlessly collapse the vessels. Each session is spaced two to four weeks apart, and this includes five to 150 injections. Spider Veins are a common problem. They are small, purplish-red veins that can start anywhere on the leg. They can start from your ankle to the top of the leg and look similar to a spider web. Many people feel very uncomfortable when these veins become visible to the public. Varicose Veins Sclerotherapy is similar to that of the treatment of spider veins. The same type of injection is made several times to collapse the vessel. Each session is also spaced two to four weeks apart. The amount of injections are also the same in a half an hour time span. If you choose to have an hour time span, of course there will be an increase of injections to the area. Varicose veins are larger than the spider veins. These veins are normally raised, blue in color, and are quite painful. Painful in the sense of actual throbbing, pulsing, or a burning sensation when standing for long periods of time. If left untreated, varicose veins can lead to blood clots, phlebitis or even ulcers. No one has really determined why people have varicose veins and spider veins except that heredity, obesity, heat, birth control pill/estrogen, and strenuous exercise play a role in this condition. Trauma is also a pre-determined condition to why some people may have these varicose or spider veins.