Spider veins are often caused by genetics, prolonged standing, or hormonal changes.

Spider veins develop from a backflow of blood in the veins. This condition, which results from damaged valves in the veins, is called “venous reflux.” As blood collects in these veins, their walls distend. This increases the size of the veins, and makes them visible under the surface of the skin. Risk factors for developing spider veins include the following:

• Increasing age
• Hormonal changes
• Pregnancy
• Obesity
• Lack of exercise
• Sun exposure

Having a family history of spider veins is also a risk factor for developing them.

Spider veins, which are diagnosed through a physical examination of the patient, an analysis of symptoms and, sometimes, diagnostic ultrasound, can be treated in a number of ways, all of which are minimally invasive.