What are Spider Veins?

Spider veins are small, dilated blood vessels near the surface of the skin measuring between 0.5 and 1 millimeter in diameter. Spider veins get their name because they look like spider webs or tree branches. They are red, blue or purple in color. They can develop anywhere on the body but are commonly seen on the face or legs. When they occur on the legs, they often have underlying venous reflux or “hidden varicose veins.” When found on the legs, they are often found specifically on the upper thigh, below the knee joint, and around the ankles.

Who is Affected by Spider Veins?

30 to 40 million Americans suffer from venous insufficiency, the cause of both varicose and spider veins.

Contributing factors include heredity, gender, age, weight, pregnancy, history of deep vein thrombosis (blood clots), and standing or sitting for long periods of time. Additional factors seen to cause spider veins include smoking, exposure to heat (hot tubs, baths, saunas), and tight clothing.

In addition:

  • Close to 50% women ages 40 to 50 have spider veins and about 75% of women ages 60 to 70
  • Around 25% of men age 30 to 40 have spider veins and about 50% of men over the age of 70

How are Spider Veins Diagnosed?

Spider veins are often diagnosed through a physical exam. Your doctor will examine your legs and visible veins while you’re sitting as well as standing.  Some additional exams can include:

Duplex ultrasound. A type of vascular ultrasound done to check blood flow and the structure of the leg veins. Duplex means 2 types of ultrasound are used.

Magnetic resonance venography (MRV). A diagnostic procedure that uses a combination of large magnets and a computer to view the veins. Dye is injected into the veins to better see them. MRV can also help to diagnose other causes of leg pain.