Varicose veins are swollen, twisted veins visible just beneath the skin, most commonly in the legs. They signal that blood is flowing backward and pooling in your veins instead of returning efficiently to your heart. While they affect 10 to 30% of the world’s population and are often dismissed as cosmetic, they represent a real change in how your circulatory system is functioning and can progress to more serious problems over time.
What Is Actually Happening Inside the Vein
Your leg veins contain one-way valves that open to let blood flow upward toward the heart and snap shut to prevent it from falling back down. When those valves stop working properly, blood pools in the vein below, raising the pressure inside it. Over time, that sustained pressure stretches and distorts the vein wall, creating the bulging, rope-like appearance you see on the surface.
There are two competing explanations for why this starts. The older theory blames the valves themselves: once one valve fails, the increased pressure damages the next valve down, and the problem cascades. The newer, increasingly supported theory points to the vein wall itself. Histological studies show that varicose veins have a disrupted muscle layer, with some of the most affected segments losing their muscle tissue entirely, leaving only collagen and elastic fibers. Without that muscular structure, the vein can’t maintain its shape or tone under pressure.
There’s growing evidence that varicose veins reflect a body-wide issue with connective tissue rather than a purely local problem in the legs. Smooth muscle cells taken from varicose veins produce too much of one type of collagen and too little of another. Remarkably, skin cells taken from people with varicose veins (not from the veins themselves, but from ordinary skin) show the same imbalance. This suggests a genetic predisposition in how your body builds and maintains connective tissue.
Who Gets Them and Why
The strongest risk factors are ones you can’t change. Genetics play a major role: a large-scale genetic study identified 12 specific gene regions associated with varicose veins, with nearly 27% of the inherited risk traced to a single gene involved in blood vessel development. Age matters too, since vein walls naturally lose elasticity over time. Women develop varicose veins more often than men, partly due to hormonal effects on vein walls and partly because pregnancy dramatically increases blood volume and pressure in the leg veins.
Height is an independent risk factor, even after accounting for weight. Taller people have longer columns of blood pressing down on their leg veins, which translates to higher baseline venous pressure. Weight, waist circumference, and hip circumference are all causally linked to varicose vein development, not just correlated with it. Jobs that involve prolonged standing or heavy manual labor increase risk, while a faster walking pace is actually associated with lower risk. Smoking shows a positive correlation as well.
How Varicose Veins Feel
Not everyone with varicose veins has symptoms. Some people notice only the visual change. But when symptoms do appear, they follow a distinctive pattern that differs from ordinary muscle soreness or joint pain. The hallmark is a heavy, achy feeling in the legs that worsens after sitting or standing in one position for a long time and improves when you elevate your legs or walk around. You may also notice burning, throbbing, muscle cramping, and swelling in the lower legs. Itching around the affected veins is common and results from inflammation in the skin above the pooling blood.
The key distinction from normal fatigue or aging-related aches: varicose vein symptoms are position-dependent. They reliably get worse with gravity (standing, sitting with legs down) and better when you counteract it (walking, elevating). If your leg pain doesn’t follow that pattern, something else is likely going on.
How the Condition Progresses
Varicose veins exist on a spectrum of chronic venous disease that ranges from purely cosmetic spider veins to open wounds that won’t heal. The progression typically moves through recognizable stages. It starts with small spider veins or visible blue-green veins under 3 millimeters in diameter. Once veins dilate beyond 3 millimeters and begin to bulge, they qualify as true varicose veins. From there, persistent swelling can develop in the lower legs, followed by skin changes: darkening or discoloration (caused by the breakdown of red blood cells and iron deposits in the skin), eczema-like irritation, and eventually a hardening and thickening of the skin called lipodermatosclerosis. In the most advanced stages, the skin breaks down into venous ulcers, which are slow-healing open sores typically found near the ankle.
This progression isn’t inevitable. Many people live with varicose veins for decades without advancing beyond the early stages. But the condition doesn’t reverse on its own, and each stage makes the next more likely.
The Connection to Blood Clots
The most important thing varicose veins “mean” from a health standpoint is an elevated risk of blood clots. A large study published in JAMA found that people with varicose veins had a five-fold higher rate of deep vein thrombosis (DVT) compared to matched controls: 6.55 cases per 1,000 person-years versus 1.23. They also had a 73% higher risk of pulmonary embolism, a potentially life-threatening condition where a clot travels to the lungs. The risk of peripheral artery disease was 72% higher as well.
These numbers don’t mean varicose veins will cause a blood clot. The absolute risk remains relatively low for most individuals. But they do mean that varicose veins are not purely cosmetic. The same sluggish blood flow and vein wall damage that create visible varicose veins also create conditions where clots are more likely to form.
How They Are Diagnosed
A visual exam can identify varicose veins, but understanding what’s happening beneath the surface requires an ultrasound. The standard test is a duplex ultrasound, which combines a traditional image of the vein’s structure with a measurement of blood flow direction and speed. The technician squeezes your calf or foot to push blood upward, then watches whether it flows back down when the pressure is released. If blood flows backward (refluxes) for longer than about half a second to one second, the valve at that point is considered incompetent. This test maps which veins are affected and how severely, which determines what treatment makes sense.
Managing Varicose Veins
Treatment falls into two broad categories: managing symptoms conservatively, or closing off the damaged veins so blood reroutes through healthier ones.
Compression Stockings
Graduated compression stockings are the first-line approach. They apply the most pressure at the ankle and gradually decrease toward the knee or thigh, helping push blood upward. For uncomplicated varicose veins with symptoms like aching and mild swelling, stockings in the 15 to 20 mmHg range have been shown to significantly reduce discomfort and improve quality of life compared to no compression. For more advanced disease with skin changes, or for preventing ulcer recurrence, higher-pressure stockings in the 30 to 40 mmHg range are more effective. The trade-off is that higher compression is harder to put on and less comfortable, so the “best” compression level is often the highest one you’ll actually wear consistently.
Procedures to Close Damaged Veins
When compression isn’t enough, several procedures can seal off malfunctioning veins. The two most common minimally invasive options are laser ablation (heat delivered through a thin fiber inserted into the vein) and foam sclerotherapy (a chemical foam injected to irritate and collapse the vein wall). Both are typically done in an office setting without general anesthesia.
Laser ablation has a significantly higher success rate for completely closing the treated vein. In a head-to-head trial, laser ablation was nearly five times more likely to achieve full closure of the great saphenous vein (the large vein running up the inner leg) compared to foam sclerotherapy at six months. Patients in the laser group also reported fewer residual varicose veins. However, foam sclerotherapy has a notable advantage in recovery experience: patients recalled significantly less pain during and after the procedure compared to both laser ablation and traditional surgery.
Traditional surgical stripping, where the vein is physically removed, had the lowest rate of needing follow-up treatments (about 1% required additional procedures versus 14% for foam and 31% for laser). But surgery involves more extensive recovery and is generally reserved for cases where minimally invasive options aren’t suitable.
Regardless of the method, closing off a varicose vein doesn’t harm your circulation. The superficial veins that become varicose carry only a small fraction of your leg’s blood. Once sealed, blood simply flows through the deeper venous system, which handles the vast majority of return flow already.
What You Can Do to Slow Progression
Since prolonged standing and excess weight are causal risk factors, the most effective lifestyle changes target those directly. If your job requires standing, shifting your weight, flexing your calves, and taking walking breaks all activate the calf muscle pump that pushes blood upward. Regular walking at a brisk pace is associated with lower risk. Maintaining a healthy weight reduces the pressure your abdominal and leg veins have to work against. Elevating your legs above heart level for 15 to 20 minutes when you can gives your valves a break from fighting gravity. None of these will reverse existing varicose veins, but they can meaningfully reduce symptoms and slow the progression toward more advanced stages of venous disease.