Spider Veins: Causes, Symptoms, and Treatment
Life with Spider Veins
Though unsightly and often discomforting and painful, spider veins are an incredibly common symptom of chronic venous insufficiency. Here, we'll tell you everything you need to know about this vein condition.

What are they?
Spider veins are small, dilated blood vessels near the surface of the skin measuring between 0.5 – 1 millimeter in diameter. Commonly seen on the face or legs, spider veins get their name because they look like spider webs or tree branches, and they're almost always red, blue, or purple in color. When they occur on the legs, spider veins are usually found on the upper thigh, below the knee joint, and around the ankles, and they often have underlying venous reflux or “hidden varicose veins."
Who do they affect?
Tens of millions of Americans suffer from spider veins. Contributing factors include heredity, gender, age, weight, pregnancy, history of deep vein thrombosis (DVT and blood clots), and standing or sitting for long periods of time. Additional factors that may cause spider veins include smoking, exposure to heat (hot tubs, baths, saunas), and tight clothing.
In addition:
- Close to 50% of women ages 40 to 50 have spider veins
- About 75% of women ages 60 to 70 have spider veins
- Around 25% of men age 30 to 40 have spider veins
- Close to 50% of men over the age of 70 have spider veins
How are they 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.
Ways to Test for Spider Veins
Duplex ultrasound
A type of vascular ultrasound done to check blood flow and the structure of the leg veins.
Color-flow imaging (also called triplex ultrasound)
A procedure similar to duplex ultrasound that uses color to show the direction of blood flow.
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. An MRV can also help diagnose other causes of leg pain.