Those thin red, blue, or purple lines that fan out across your thighs, calves, or ankles have a name: spider veins, or telangiectasias. They are extremely common, especially in women, and most people first notice them in summer — right when shorts and swimsuits come out of the closet. The good news is that spider veins are usually harmless and very treatable in a short office visit. The important part is making sure nothing bigger is going on underneath. At Northwest Cardiovascular Clinic, we evaluate and treat spider veins for patients across Cypress, Tomball, Spring, and northwest Houston. Here is what you should know.
What exactly are spider veins?
Spider veins are tiny blood vessels — mostly small venules, along with some capillaries — that have permanently widened and become visible just beneath the surface of the skin. They typically measure less than a millimeter or two across, sit flat against the skin rather than bulging, and often spread out in a branching, web-like pattern that gives them their name.
They are not the same thing as varicose veins. Varicose veins are larger, ropey, and raised above the skin, and they usually cause more symptoms. But the two are related: both are part of the same spectrum of vein disease, and spider veins are often the earliest visible sign of a deeper circulation problem called chronic venous insufficiency.
What causes spider veins?
Spider veins develop when the pressure inside small surface veins stays too high for too long, stretching the vessel walls until they stay dilated. Several things raise your risk:
- Being female. Women are several times more likely than men to develop spider veins, largely because of the effect estrogen and progesterone have on vein walls.
- Pregnancy. Increased blood volume and hormonal shifts make pregnancy one of the most common triggers.
- Family history. If your mother or grandmother had them, your odds go up considerably.
- Long hours on your feet — or in a chair. Teachers, nurses, hairstylists, retail workers, and anyone who sits at a desk all day are all at higher risk, because the calf muscles are not pumping blood upward.
- Age. Vein valves and vessel walls naturally weaken over time.
- Extra weight, which increases pressure in the leg veins.
- Sun exposure, which contributes to spider veins on the face more than the legs.
- Smoking and a personal history of blood clots have also been linked to spider vein development.
Are spider veins dangerous?
On their own, spider veins are almost always a cosmetic issue rather than a medical one. They do not rupture the way large varicose veins occasionally can, and they do not cause blood clots.
What matters is what they may be pointing to. In a meaningful number of people, visible spider veins are the surface signal of underlying venous reflux — leaky one-way valves in the larger veins deeper in the leg that allow blood to flow backward and pool. That is why we pay attention when spider veins come with symptoms. Talk to a doctor if you also notice:
- Aching, throbbing, or a heavy, tired feeling in your legs, especially at the end of the day
- Swelling around the ankles or lower legs
- Night cramps or restless legs
- Itching or burning over the veins
- Brown or reddish discoloration of the skin near the ankle
- Any open sore or ulcer near the ankle that is slow to heal
Those signs suggest the problem runs deeper than the skin, and treating only the surface veins in that situation tends to disappoint — they simply come back.
How spider veins are evaluated
A proper evaluation starts with a conversation about your symptoms and history, followed by an exam of your legs while you are standing, which is when veins are most visible. If there is any suggestion of a deeper problem — symptoms, larger bulging veins, swelling, or skin changes — we recommend a venous duplex ultrasound.
Duplex ultrasound is painless, takes about 30 to 45 minutes, and uses sound waves to show both the structure of your veins and the direction blood is flowing in them. It is the standard test for diagnosing venous reflux, and it tells us whether your spider veins are an isolated cosmetic finding or the visible tip of something larger. Because our clinic offers the full range of vein treatment services, we can do the ultrasound and the treatment in the same office.
Sclerotherapy: the standard treatment for spider veins
Sclerotherapy is considered the gold-standard treatment for spider veins on the legs, and it has been used for decades. A very fine needle is used to inject a small amount of a medication called a sclerosant directly into the vein. The solution irritates the lining of the vessel, causing it to swell shut and seal. Over the following weeks your body gradually absorbs the closed vein, and it fades from view. Blood simply reroutes through the many healthy veins nearby.
Here is what a typical treatment looks like:
- Time. Most sessions take about 20 to 30 minutes, depending on how many veins are treated.
- Comfort. The needles are very small. Most people describe a brief sting or a mild cramping sensation as the solution goes in. No anesthesia is needed.
- Afterward. You will typically wear compression stockings for a few days to a couple of weeks, and we will ask you to walk regularly. Avoid hot baths, hot tubs, and strenuous exercise for a short period.
- Downtime. There is essentially none. Most patients drive themselves home and return to work the same day.
How many treatments will you need?
Spider veins do not vanish overnight, and honest expectations matter here. Each session typically clears somewhere in the range of 50 to 80 percent of the treated veins, and most people need two to four sessions spaced several weeks apart to be happy with the result. A small, isolated cluster is sometimes handled in a single visit.
Results also take time to appear. Treated spider veins usually fade over roughly three to six weeks, while larger vessels can take a few months. It is normal for the area to look a little worse before it looks better.
Finally, treatment closes the veins you have — it does not change the underlying tendency to form them. New spider veins can appear over the years, particularly if the risk factors are still in play, and many patients come back for a touch-up session down the road.
What about side effects?
Sclerotherapy has a strong safety record, but no procedure is free of side effects, and you should know what is normal:
- Bruising, redness, and small raised welts at the injection sites are common and settle within days.
- Brown discoloration along the treated vein happens in a minority of patients as iron from the trapped blood settles in the skin. It usually fades on its own over several months, and the large majority resolves within a year.
- Telangiectatic matting — a fine blush of tiny new vessels near the treated area — occurs in a small percentage of patients and typically resolves on its own over 3 to 12 months.
- Rarely, a small skin ulcer, an allergic reaction to the sclerosant, or a superficial clot can occur.
Sclerotherapy is not appropriate for everyone. It is generally avoided during pregnancy and breastfeeding, in people with an active blood clot, and in certain other medical situations — which is exactly what your consultation is for.
When bigger veins need to be treated first
If the ultrasound shows significant reflux in a larger vein such as the great saphenous vein, we treat that first. Our primary tool for that is Varithena®, an FDA-approved microfoam delivered in the office without surgery or heat. Fixing the source before treating the surface veins gives a better and longer-lasting cosmetic result — and when veins are causing symptoms and reflux is documented, that portion of care is often covered by insurance. Purely cosmetic spider vein treatment generally is not covered, and our team will tell you where you stand before you commit to anything.
Can you prevent spider veins?
You cannot change your genetics or your age, but a few habits genuinely help keep pressure off your leg veins:
- Move regularly. Walking is the single best thing you can do — your calf muscles are the pump that pushes blood back up.
- Break up long periods of sitting or standing. Shift your weight, flex your ankles, or take a two-minute walk every hour.
- Elevate your legs at the end of the day.
- Wear compression stockings if you work on your feet or travel a lot.
- Maintain a healthy weight and stay active.
- Use sunscreen to limit spider veins on the face.
When to seek urgent care
Spider veins themselves are not an emergency. But get medical care right away if you develop sudden swelling in one leg with pain, warmth, or redness (a possible blood clot), bleeding from a vein that will not stop with firm pressure and leg elevation, or an open sore near your ankle. And if leg pain comes on with walking and eases with rest, that can point to an artery problem rather than a vein problem — see our page on peripheral artery disease.
Spider vein treatment in Cypress & Tomball
Northwest Cardiovascular Clinic is located just off SH 249 (Tomball Parkway) in northwest Houston, caring for patients throughout Cypress, Tomball, Spring, and the greater Houston area. Dr. Ismail Dairywala is a board-certified cardiovascular specialist, and because we evaluate the heart, the arteries, and the veins under one roof, we can tell you whether your spider veins are purely cosmetic or a sign that the deeper veins need attention — and treat either one without sending you elsewhere.
If you are tired of covering up your legs, contact our office to schedule a vein consultation. It usually takes less than you think to see a real difference.
Frequently asked questions
What causes spider veins on the legs?
Spider veins form when small surface veins stay under high pressure and permanently widen. The biggest contributors are being female, pregnancy, family history, age, extra weight, and spending long hours standing or sitting without moving your calf muscles. Smoking and a history of blood clots have also been linked to them.
Are spider veins dangerous?
On their own they are almost always cosmetic rather than dangerous. What matters is what they may signal — in some people they are the first visible sign of venous reflux in the deeper leg veins. If your spider veins come with aching, heaviness, swelling, night cramps, itching, or skin discoloration near the ankle, have them evaluated.
How does sclerotherapy for spider veins work?
A very fine needle delivers a small amount of a medication called a sclerosant into the vein. The solution irritates the vessel lining so it seals shut, and over the following weeks your body absorbs the closed vein while blood reroutes through healthy veins nearby. Sessions usually take 20 to 30 minutes with essentially no downtime.
How many sclerotherapy sessions will I need?
Most people need two to four sessions spaced several weeks apart, with each session typically clearing about 50 to 80 percent of the treated veins. A small isolated cluster is sometimes handled in one visit. Results appear gradually — usually over three to six weeks for spider veins.
Does insurance cover spider vein treatment?
Treatment done purely for appearance is generally not covered. However, when an ultrasound documents venous reflux and your veins are causing symptoms such as aching, heaviness, or swelling, treating the underlying vein is often considered medically necessary and covered. Our team verifies your benefits before you commit to anything.
Where can I get spider vein treatment near Cypress or Tomball?
Northwest Cardiovascular Clinic treats spider and varicose veins at our office just off SH 249 in northwest Houston, serving Cypress, Tomball, Spring, and the surrounding communities. We perform the venous ultrasound and the treatment in the same place. Call (281) 807-5253 to schedule a consultation.