Similar to leaky pipes, veins, as they return blood to the heart, sometimes fail to close completely. They stretch out and subsequently leak near the surface of the skin, creating spider or varicose veins that may cause discomfort.

Dr. Tanya Flohr, a vascular surgeon at Penn State Heart and Vascular Institute, said the majority of people who come into her office with spider and varicose veins are concerned they may cause blood clots.

“Varicose veins are less likely to develop into bloodclots because they are superficial veins,” she said. “But they may hurt and become infected.”

The older someone is, the more likely they are to develop varicose veins. Women—especially those who are pregnant, sedentary people and smokers have a higher risk.

Genetics also play a role. “If both of your parents have them, there is a 90 percent chance that you will,” Flohr said.

Aside from staying active and maintaining a healthy weight, little can be done to prevent varicose veins, nor do they go away once they appear.

Flohr recommends people who are at risk take breaks from work and sit down or elevate their legs if they spend a lot of time on their feet. Also, they should avoid crossing their legs.

Varicose veins often occur in the lower extremities but can pop up anywhere.

“They aren’t painful, but they can result in discoloration and changes to surrounding tissue that can become an irritant,” she said.

For patients who experience pain or a nondescript, heavy, achy feeling in their legs, Flohr recommends a vascular evaluation.

“We do an ultrasound, look at the arteries, and look at both the deep and superficial veins to see how well they are working,” she said.

Use of compression stockings that reach to the knees or higher can help minimize discomfort and slow the development of new varicose veins.

If symptoms persist and warrant it, surgery to close off the vein is an option. Vascular surgeons can thread small catheters with laser tips or microwave probes through veins to heat them up from the inside, causing them to close and reroute blood. Or they can deliver glue to the interior of the veins to close them off without use of numbing medication or heat.