For venous conditions such as broken capillaries and spider veins, sclerotherapy offers an effective alternative to diathermy or laser treatments. For fair-skinned people, women in particular, capillaries may be the result of genetics or sun damage.

It works by injecting the unwanted blood vessels with a sclerosing solution that causes the target capillary to shrink and then dissolve over a period of weeks as the body naturally absorbs the treated vein.

Sclerotherapy is preferred to laser for eliminating large spider veins (telangiectasiae) as well as smaller varicose leg veins. Unlike a laser, the sclerosing solution additionally closes the feeder veins under the skin that cause the spider veins to form, making a recurrence of the spider veins in the treated area less likely. A single blood vessel may have to be injected more than once, some weeks or months apart, depending on its size. A number of vessels can be injected in any one-treatment session.

While it is a simple treatment, injecting the veins requires a high degree of skill and accuracy. It is important to seek treatment from a properly qualified practitioner.