“Spider veins” are characterised by thin hair-like veins that usually appear on the legs or face. The condition, is generally harmless and painless but one might find its appearance undesirable.

Spider veins occur when the walls of small, superficial, microscopic blood vessels in the legs or face become weakened and thus dilate and become visible. The cause is strongly genetic, but this can be aggravated by an increased pressure in the blood vessels caused by obesity, age, pregnancy, hormonal imbalances or other genetic factors.

Telangiectasias are characterised by blue or red spider web-like appearance and reticular veins are slightly larger spider veins but still part of the microcirculation.


In 5-10% of patients with spider veins, there may be malfunctioning valves of the deeper veins, which can eventually cause varicose veins. One should note that spider veins congesting the feet, are more likely to be from a deeper vein issue, and a duplex doppler scan is indicated in this event.

However, in most people the spider veins are limited to the microcirculation and further investigation is not necessary. The very superficial veins are treated on their merits, but there is often a ‘feeding’ vein which needs to be identified as well.

Spider Vein treatment

Spider veins may be treated by sclerotherapy, laser and radiofrequency.

The commonest treatment of the lower legs is sclerotherapy.


During sclerotherapy, a sclerosant medication is injected directly into the identified vein and its branches. The medicine irritates the vein walls, and they collapse and seal off, thus eventually rendering them invisible.

One may need multiple sclerotherapy session to effectively get rid of spider veins.


One needs to have realistic expectations. When a sclerosant is injected, the veins disappear, however, these veins refill with blood again once the sclerosant has washed out and will initially go darker than before. Statistics report that one should expect to see results in 3 to 6 weeks. Larger veins may take up to 3 to 4 months (see below). Studies have shown an overall success rate of 50 – 80 % for injection therapy.

Side Effects


The chemical used to treat spider veins can sometimes leave pigmentation. Treating bigger veins does increase the risk. In most people this will go away but can take weeks to months or up to a year and in a small percentage of people it is permanent.
Compression stockings, and avoiding sun will decrease this risk.


This is a very rare complication but a small wound (ulcer) may develop at the site of injection. This typically occurs if sclerosant is injected into the tissue around a vein or into a small artery. It is managed with wound care and usually compression.

Allergic Reaction

As a foreign chemical is being injected into the body, there is the possibility of an allergic reaction and other side effects of the chemical, however, this is extremely uncommon.

See other common conditions