Varicose veins are swollen, twisted veins that bulge beneath the skin, most commonly in the legs. About 23% of U.S. adults have them, making them one of the most common vascular conditions. They develop when the tiny one-way valves inside your veins stop working properly, allowing blood to pool and stretch the vein walls outward.
How Varicose Veins Form
Your leg veins have a tough job: they push blood upward against gravity, back toward your heart. To prevent that blood from sliding back down between heartbeats, veins contain small flap-like valves that snap shut after each pulse of blood passes through. When those valves weaken or fail, blood flows backward (a process called reflux) and collects in the vein below. The extra volume increases pressure inside the vein, gradually stretching it wider.
Once a vein dilates enough, the valve flaps can no longer meet in the middle. That makes the problem self-reinforcing: a stretched valve lets more blood pool, which stretches the vein further, which damages the next valve down. This is why varicose veins tend to worsen over time rather than improve on their own. The pressure can also force blood from the deep veins in your legs backward into the surface veins, which weren’t built to handle that force. Those surface veins then bulge visibly under the skin.
What They Look and Feel Like
Varicose veins appear as raised, rope-like cords that are usually blue or dark purple. They twist and bulge along the surface of the leg, most often on the calves and inner thighs. Some people have a single noticeable vein; others develop clusters.
Not everyone with varicose veins has symptoms beyond the visible bulging. But many people experience a heavy, aching sensation in the legs that gets worse after long periods of standing or sitting. Other common symptoms include throbbing or cramping in the lower legs, itching around the vein, and swelling in the ankles or feet by the end of the day. The discomfort tends to ease when you elevate your legs.
Varicose veins are different from spider veins, which are much smaller, flat, and closer to the skin’s surface. Spider veins look like thin red or blue webs and rarely cause pain. If spider veins and these smaller reticular veins are counted alongside varicose veins, up to 80% of men and 85% of women have some form of visible vein changes.
Who Gets Them and Why
Varicose veins affect roughly twice as many women as men. Between the ages of 40 and 80, an estimated 22 million women and 11 million men in the U.S. deal with them. Several factors raise your risk:
- Family history. Genetics play a major role. Researchers have identified at least 30 genes associated with varicose vein development. If one or both of your parents had them, your chances increase significantly.
- Pregnancy. Blood volume rises during pregnancy to support the growing baby, and hormonal changes relax vein walls. The expanding uterus also puts pressure on the large veins in the pelvis, slowing return blood flow from the legs. The good news: for most women, pregnancy-related varicose veins shrink after delivery.
- Prolonged standing or sitting. Jobs that keep you on your feet or at a desk for hours reduce the natural pumping action of your calf muscles, which normally helps push blood upward.
- Age. Vein valves wear out over time. The condition becomes progressively more common with each decade of life.
- Height. Taller individuals have longer columns of blood in their leg veins, which means greater downward pressure on those valves.
- Smoking and hormone therapy. Both are confirmed risk factors, likely because of their effects on blood vessel walls and clotting.
Potential Complications
Most varicose veins are more of a nuisance than a danger, but ignoring them for years can lead to more serious problems. Chronic high pressure in the veins can cause the skin around your ankles to become discolored, hardened, and fragile. Over time, this damaged skin can break down into venous ulcers, which are shallow, irregularly shaped sores that ooze fluid, itch, and sometimes smell. These ulcers can take several months to heal, and in severe cases, they never fully close.
Varicose veins can also develop superficial blood clots, a condition called superficial thrombophlebitis. The vein becomes red, warm, and tender to the touch. While these surface clots are usually not dangerous on their own, varicose veins are a recognized risk factor for deeper clots. Sudden, significant swelling in one leg, or a varicose vein that starts bleeding, warrants prompt medical attention.
How Varicose Veins Are Diagnosed
A doctor can often identify varicose veins just by looking at your legs while you’re standing. To determine which valves are failing and how severe the reflux is, the standard test is a duplex ultrasound. This painless scan uses sound waves to create a real-time image of blood flowing through your veins. The technician can see exactly where blood is flowing backward and measure how much reflux is occurring. The results help guide treatment decisions.
Treatment Options
Mild varicose veins that cause little discomfort are often managed with lifestyle changes. Compression stockings apply graduated pressure to the legs, helping veins move blood upward more efficiently. Regular walking, elevating your legs when resting, and avoiding long stretches of standing or sitting all reduce symptoms. Losing excess weight takes pressure off the veins in your pelvis and legs.
When symptoms are more bothersome or complications develop, several procedures can close off or remove the damaged veins. Blood simply reroutes through nearby healthy veins.
The most common modern approach is a heat-based procedure where a thin tube is inserted into the vein through a tiny incision. The tube delivers targeted heat energy that seals the vein shut from the inside. Because the vein is left in place rather than physically pulled out, recovery is fast. Most people return to work within a few days, though physically demanding jobs may require a bit more time off. Complications are fewer than with older surgical techniques.
Traditional vein-stripping surgery, which removes the damaged veins through several incisions, is still performed in certain cases but has largely been replaced by less invasive options. Recovery from stripping typically takes several weeks rather than days.
For smaller varicose veins, a doctor may inject a solution directly into the vein that irritates the lining and causes it to collapse and fade. This is done in an office setting without anesthesia and works well for veins that aren’t large enough to warrant a heat-based procedure.
Living With Varicose Veins
Because valve damage is permanent once it occurs, varicose veins tend to be a long-term condition. Even after successful treatment, new varicose veins can develop in other locations over the years, especially if the underlying risk factors (genetics, prolonged standing, excess weight) remain. Consistent use of compression stockings, regular exercise, and periodic leg elevation are the most effective ways to slow progression and manage discomfort day to day.