Thread veins, also known as spider veins, are very small veins within the skin that have become dilated. This causes them to have a bluish, reddish or purplish appearance, which is visible through the skin.

There are many suspected causes of thread veins, although no one set of causes is definitively known. The following could be causes of thread veins:

• Genetics – thread veins are often inherited, so you will find them in the same members of the same family. Identical twins often both have thread veins. If your parents have them, it is likely that you may get them too.
• Smoking and drinking
• Prolonged standing
• Hormonal factors – women who are pregnant may experience thread veins at some point during their pregnancy
• Exposure to sunlight
• Radiotherapy treatment for cancer
• Injuries and cuts

There isn’t too much you can do to prevent thread veins from forming, but you can get them treated if you choose to. Thread veins aren’t dangerous or harmful, but some people find their appearance to be unattractive and unsightly.

If you have thread veins and you aren’t happy to simply live with them, you can get them treated effectively and non-invasively via a course of laser treatment.