Spider veins are small, widened blood vessels visible just under the surface of your skin. Less than 1 millimeter wide, they appear as thin red, blue, or purple lines that branch out in clusters resembling a spiderweb or tree branches. Their medical name is telangiectasia, and while they’re extremely common and usually harmless, they can sometimes signal changes worth paying attention to in your circulatory system.
What Causes Spider Veins
Spider veins form when tiny blood vessels near the skin’s surface weaken and expand. Healthy veins have small valves that keep blood flowing in one direction. When those vessel walls lose strength, blood can pool slightly, causing the vein to dilate and become visible through the skin.
Several factors make this more likely to happen:
- Genetics: If close family members have spider veins or varicose veins, your odds go up significantly. The tendency toward weaker vessel walls runs in families.
- Hormonal changes: Pregnancy, hormonal birth control, and hormone therapy for menopause all increase risk. Fluctuating hormone levels can relax vein walls, making them more prone to expanding.
- Prolonged standing or sitting: Staying in one position for long stretches forces your veins to work harder against gravity, especially in the legs.
- Injury or trauma: A bump, surgical incision, or other damage to the skin can trigger spider veins in that area.
- Connective tissue diseases: Conditions that affect the structural proteins in your body can weaken blood vessel walls more broadly.
Where They Appear and What They Feel Like
Spider veins show up most often on the legs and face, though they can develop anywhere. On the legs, they tend to cluster behind the knees, on the thighs, or around the ankles. On the face, they commonly appear around the nose and cheeks.
Most spider veins cause no physical symptoms at all. They’re a cosmetic concern for many people, but they don’t itch, swell, or ache the way their larger cousins (varicose veins) often do. In rare cases, people report mild burning or discomfort around clusters of spider veins, but this is uncommon enough that any persistent pain or swelling in the area is worth investigating for other causes.
Spider Veins vs. Varicose Veins
People often confuse spider veins with varicose veins, but the two are quite different in size, appearance, and impact. Spider veins are less than 1 millimeter wide and sit flat or barely raised against the skin. Varicose veins are more than 3 millimeters wide and bulge outward, creating visible lumps or ropey ridges you can feel with your fingers.
The symptom picture is also different. Varicose veins frequently cause itching, pain, swelling, heaviness in the legs, and in severe cases, skin ulcers. Spider veins are typically painless. Varicose veins are limited to the legs, feet, and ankles, while spider veins can appear on the face and other areas of the body. Both can be red, blue, green, or purple, but varicose veins always look three-dimensional, while spider veins are mostly flat.
Having spider veins doesn’t mean you’ll develop varicose veins, though the two share overlapping risk factors. If you notice veins becoming raised, painful, or swollen, that points toward varicose veins and possibly underlying circulation problems rather than simple spider veins.
Treatment Options
Because spider veins rarely cause medical problems, treatment is optional and usually motivated by appearance. Two main approaches dominate.
Sclerotherapy
This is the most common treatment. A provider injects a solution directly into the spider vein, which irritates the vessel wall and causes it to collapse. Your body then gradually absorbs the closed vein over the following weeks. Research shows sclerotherapy clears spider veins in 75 to 90 percent of cases, though it typically takes multiple sessions to fully collapse a vein. You may need several appointments spaced weeks apart to treat all the veins in an area.
Laser Treatment
Laser therapy uses targeted heat to seal the vein shut from the outside. Once the vein closes, your body reabsorbs it and it fades from view. Laser treatment works well for very small spider veins and for veins on the face, where injections can be tricky. One potential downside is pigment changes in the surrounding skin. Some people develop darker or lighter patches near the treatment area, and this risk is harder to predict across different skin types and tones.
Neither treatment is permanent in the sense that it prevents new spider veins from forming. The treated veins won’t come back, but new ones can develop over time if the underlying causes (genetics, hormones, lifestyle) remain.
Reducing Your Risk
You can’t fully prevent spider veins, especially if genetics are working against you. But several habits slow their development and keep existing ones from worsening.
Regular exercise is one of the most effective strategies. Walking, strength training, and stretching all improve circulation and strengthen blood vessel walls. You don’t need intense workouts. Consistent movement throughout the day matters more than occasional hard sessions. If your job requires long periods of standing or sitting, changing positions frequently and elevating your legs when possible makes a real difference.
Smoking weakens veins and blood vessels over time, so quitting reduces your risk. Maintaining a healthy weight takes pressure off your blood vessels, particularly in the legs. An anti-inflammatory diet rich in fiber and antioxidants may also help protect vein health, though the evidence here is less direct.
Compression stockings can help prevent new spider veins from forming by supporting blood flow in the legs. They’re available over the counter in various pressure levels, or a provider can prescribe a specific fit. One less obvious tip: avoid tight clothing around areas where you already have spider veins, as constricting pressure in the wrong spot can impair circulation rather than help it.
Some providers also recommend supplements like horse chestnut extract to manage discomfort associated with spider veins. Other options that may support vein health include diosmin and hesperidin, plant-based compounds that help strengthen blood vessel walls. These aren’t substitutes for the lifestyle changes above, but they can be a useful addition for people looking for extra support.