From the outside, your veins look like nothing more than a few faint blue lines under your skin. But inside your body, they work hard to transport blood from your organs to your heart. Sometimes, blood can get stuck in your veins and make them swell up so they really stick out. These swollen veins are called varicose veins. And if you have them, you may be putting a lot of effort into covering them up.

Veins have valves in them that prevent blood from flowing the wrong way. They're kind of like the valves in your bathroom plumbing that prevent hot water in the water heater from backing up into the cold water supply. The valves inside your veins make sure that your blood keeps flowing in the right direction, toward your heart. But if those valves aren't working correctly, blood can back up and get stuck inside a vein. As the blood collects, the vein swells.

So, what causes the valves in the veins to malfunction? Well, you may have been born with defective valves. Or, you might be putting on extra pressure on the veins in your legs if you stand for long periods of time, or you're pregnant.

When you have varicose veins, you, and your doctor, should be able to tell just by looking at them. They look like raised, thick blue or purple veins. Varicose veins can also make your legs ache and your ankles swell.

So, how are varicose veins treated?

Well, first, your doctor will recommend rest and support for your varicose veins. Avoid standing for long periods of time, and prop up your feet on a pillow or box whenever you sit. Wearing elastic support hose can also help.

If you're in a lot of pain from your varicose veins, or their appearance really bothers you, your doctor may recommend a treatment such as lasers to minimize the veins. Or, you may have a type of surgery called vein stripping. During this procedure, the surgeon threads a thin, plastic wire into each varicose vein and then pulls the vein out.

At first, varicose veins are more of a cosmetic problem than a health issue. But over time, they can get worse. Some people develop sores, inflammation from phlebitis, clots, or their varicose vein breaks. Talk to your doctor if you have varicose veins, especially if they hurt or they don't improve from wearing support hose or staying off your feet. Call your doctor right away if you have intense pain, swelling, fever, or a sore on your leg.