Has your vein specialist in Houston advised you to consider sclerotherapy treatment for your spider or varicose veins? If so, then you may have questions about the way that this procedure works and how it affects veins.
Quick Answer: After sclerotherapy, the solution damages the inner lining of the vein so its walls stick together and the vein seals shut. Over the following weeks the body treats the closed vein like a bruise: it is broken down and gradually absorbed by the immune system. Spider veins usually fade over 3 to 6 weeks, while larger veins can take 3 to 4 months or longer. Blood simply reroutes through healthy veins nearby, so circulation is not harmed.
There are very few side effects associated with vein treatment. The most common of these include mild bruising or discoloration, tenderness, or discomfort around the treated vein. The risk of serious complications during your procedure is less than 1%.
Sclerotherapy is a vein treatment that involves the injection of a solution into varicose or spider veins. The solution is formulated to irritate the walls of the vein and eventually cause it to close and fade away. Sclerotherapy is most effective on veins that are small and near to the surface of the skin. Patients often wonder if sclerotherapy will negatively impact their blood circulation. Once the treated vein closes, blood will be redirected to healthy veins in your legs, promoting better circulation.
Meet your vein specialist
Dr. Syed Raza, MD
Vascular & Interventional Radiology · Founder, Premier Vein & Vascular Center
Fellowship-trained interventional radiologist certified by the American Board of Radiology and the Royal College of Radiologists (UK). Former Chief of Interventional Radiology at UTMB Galveston and Memorial Hermann Memorial City, with 15+ years treating varicose veins, venous reflux and peripheral arterial disease.
What Happens to Treated Veins After Sclerotherapy, Step by Step
Patients often picture a vein vanishing the moment the needle comes out. In reality, sclerotherapy starts a natural healing process that unfolds over weeks. Understanding that process makes the recovery much less worrying, because most of what you see along the way is expected.
1. The lining of the vein is irritated
The sclerosant, usually a detergent-type medicine such as polidocanol or sodium tetradecyl sulfate, strips the endothelium, the thin inner lining of the vein. Within minutes the vein goes into spasm and may look paler or briefly disappear. That early change is not the final result.
2. The walls stick together and seal
Over the next hours and days the damaged walls become inflamed and adhere to each other. Compression stockings help here by keeping the walls pressed together, so less blood is trapped inside and the vein seals more cleanly.
3. The vein turns into scar tissue
Over several weeks the sealed vein turns into a thin, fibrous cord. The word sclerotherapy comes from this step: sclerosis means hardening. A treated larger vein may feel like a firm string under the skin for a while.
4. The body reabsorbs it
White blood cells called macrophages gradually break the scarred vein down and clear it away, the same way they clear a bruise. As this happens, the vein fades from view and eventually is no longer visible.
Sclerotherapy Recovery Timeline: What to Expect Week by Week
Every patient heals at a slightly different pace, and larger veins take longer than fine spider veins. The table below shows a typical course we explain to patients in clinic.
| Time after treatment | What you may notice | What it means |
|---|---|---|
| First 24 to 48 hours | Small raised bumps, redness, mild itching at injection sites | Normal local reaction to the solution |
| First 1 to 2 weeks | Bruising; veins may look darker or more noticeable | The vein is sealing and blood inside it is breaking down |
| 2 to 6 weeks | Spider veins fade; some firm, tender lumps in larger veins | Scar tissue forms and is being reabsorbed |
| 6 weeks to 4 months | Larger veins continue to fade; any brown staining begins to lighten | Reabsorption continues; time to assess the result |
| After 3 to 4 months | Final result for most treated veins | A good point to decide whether a touch-up session is needed |
The key message is patience. It is common for treated veins to look worse for a couple of weeks before they look better. Judging the result too early leads to unnecessary worry.
Normal Side Effects vs Signs of a Problem
Most reactions after sclerotherapy are temporary and settle without treatment. A few deserve a phone call to your vein team.
Expected and usually harmless
- Bruising around injection sites, fading over one to two weeks
- Mild itching or redness for a day or two
- Trapped blood, a dark, tender lump in a larger treated vein; we can often release it with a tiny needle prick to speed comfort and fading
- Hyperpigmentation, a brown line along the treated vein from iron left by broken-down blood; it usually lightens over months, though it can last longer in some people
- Matting, a blush of very fine new red vessels near the treated area, which often fades on its own or responds to further treatment
Worth calling us about
- A painful, hot, red cord along a treated vein that is spreading (superficial thrombophlebitis)
- A small blister or open sore at an injection site
- Swelling of the whole calf or ankle rather than just the treated spot
Call 911 or seek emergency care if you notice:
- Sudden swelling, pain and warmth in one calf or thigh, which may signal a deep vein thrombosis
- Chest pain, sudden shortness of breath or coughing up blood
- Hives, lip or throat swelling or difficulty breathing soon after treatment
- Sudden vision changes, severe headache, weakness or trouble speaking
Does Closing a Vein Affect Circulation in the Leg?
This is one of the most common questions we hear, and it makes sense: closing a vein sounds like it should block blood flow. The answer lies in how leg veins are arranged. The leg has a deep system of veins inside the muscles that carries most of the return flow to the heart, and a superficial network just under the skin that is connected to it by many small perforating veins.
Spider veins and varicose veins are superficial veins that have stopped working properly. Their valves leak, so instead of moving blood upward they let it pool and fall back toward the ankle. In practical terms, they are adding to the workload of the leg rather than helping it. When one of these veins is closed, the blood that would have pooled in it is picked up by nearby healthy veins and carried into the deep system, which is designed to handle it.
That is why patients with symptoms such as heaviness, aching or end-of-day swelling often feel their legs are lighter after treatment of the faulty veins. The circulation becomes more efficient, not less. The one situation where we are careful is when the deep veins themselves are blocked or scarred from an old clot; in that case some superficial veins may be acting as important bypass routes, and an ultrasound beforehand tells us which veins are safe to close.
What about veins needed for heart bypass surgery?
Some patients worry about losing a vein that a heart surgeon might want one day. Diseased, dilated varicose veins are generally not suitable for bypass grafts anyway, and spider veins are far too small. If this is a concern for you, mention it at your consultation and we will factor it into the plan.
Liquid, Foam and Ultrasound-Guided Sclerotherapy Compared
Sclerotherapy is not one single technique. The form of the medicine and the way it is delivered are matched to the size and depth of the vein, which also affects how the treated vein behaves afterward.
| Technique | Best for | How it is given | What healing looks like |
|---|---|---|---|
| Liquid sclerotherapy | Spider veins and tiny reticular veins | Very fine needle, direct injection while viewing the skin | Quick fading, usually within weeks |
| Foam sclerotherapy | Larger reticular and smaller varicose veins | Solution mixed with air or gas into a foam that displaces blood | Firm cord for a while, then gradual fading |
| Ultrasound-guided foam | Deeper feeder veins not visible on the skin | Needle guided by live ultrasound | Not visible; confirmed closed on follow-up scan |
| Varithena (polidocanol microfoam) | Larger varicose and some trunk veins | Pharmaceutical microfoam under ultrasound | Gradual closure and shrinkage over weeks to months |
For many patients with visible varicose veins, the visible surface veins are fed by a leaking trunk vein deeper in the leg. Treating the surface without addressing that source is a common reason veins seem to return. That is why we often combine techniques, for example closing a leaking saphenous vein with endovenous ablation and then clearing the remaining branches with sclerotherapy.
Aftercare That Helps Treated Veins Fade Faster
Simple aftercare makes a real difference to comfort and to how cleanly the vein closes.
- Walk for 10 to 20 minutes right after the session and keep walking daily; the calf pump keeps blood moving in the deep veins
- Wear your compression stockings as instructed, often for several days to two weeks depending on vein size
- Avoid hot baths, saunas, hot tubs and heavy leg workouts for a few days, because heat and strain dilate veins
- Protect treated areas from strong sun and tanning beds for several weeks to reduce the chance of brown staining
- Avoid long periods of sitting or standing still, and flex your ankles regularly on long drives or flights
- Use acetaminophen for discomfort if needed, and ask us before taking anti-inflammatory medicines
Most people return to work and normal routines the same day or the next day. Plan your sessions so that you are not heading to a beach vacation or a long flight within the first week or two, when bruising is most visible and walking breaks are most important. If you have a special event coming up, we can time treatment so the legs have had a few months to settle beforehand.
Can Treated Veins Come Back After Sclerotherapy?
A vein that has been fully closed and absorbed does not reopen. However, two things can make it look as if veins have returned. First, a large vein occasionally needs more than one session to close completely. Second, vein disease is a lifelong tendency, and new spider or varicose veins can form in other places over the years, especially with pregnancy, weight gain, standing jobs or a strong family history.
Most people with spider veins need two or more sessions spaced several weeks apart to reach the result they want. Planning for that from the start avoids disappointment. Periodic touch-up sessions are a normal part of maintaining results, not a sign that treatment failed.
You can lower the chance of new veins by staying active, keeping a healthy weight, avoiding long periods of standing without breaks, and wearing graduated compression on long flights or long shifts on your feet.
How We Evaluate Veins Before Sclerotherapy
At Premier Vein & Vascular Center, we do not treat a vein just because it is visible. We first make sure sclerotherapy is the right tool for that vein.
- Focused history. We ask about symptoms such as aching, heaviness, swelling or night cramps, previous vein treatments, pregnancies, clotting history and medicines.
- Examination. We look at the pattern of spider veins, reticular veins and varicose veins and check for swelling, skin changes and ankle discoloration.
- Venous duplex ultrasound when needed. If you have symptoms, larger veins or clusters around the knee or ankle, our accredited vascular lab maps the veins to look for hidden reflux feeding the surface veins.
- A clear plan. We explain which veins we will treat, in what order, how many sessions to expect and what recovery will involve, so you know what the weeks after treatment should look like.
Sclerotherapy With a Vein Specialist in Houston
If you are considering sclerotherapy, or you had it elsewhere and the veins keep returning, an assessment with a vein doctor in Houston can clarify whether a deeper source needs attention first. Dr. Syed Raza, a fellowship-trained interventional radiologist with more than 15 years of experience treating vein disease, reviews your veins in our IAC-accredited vascular lab and tailors treatment to your legs. Learn more about sclerotherapy, spider vein treatment and ultrasound-guided foam sclerotherapy. Same-week appointments are usually available for patients across Houston and Katy.
Talk With a Specialist at Premier Vein
Have questions about your symptoms or treatment options? Dr. Syed Raza and the team at Premier Vein & Vascular Center can evaluate your concerns and explain your options clearly. Same-week appointments are usually available, and most insurance plans are accepted.
Frequently Asked Questions
Why do my veins look worse after sclerotherapy?
In the first one to two weeks, treated veins often look darker or bruised because blood inside them is breaking down while the vein seals. This is part of normal healing. Most spider veins fade over the following weeks, and larger veins over a few months.
How many sclerotherapy sessions will I need?
Many patients need two or more sessions spaced several weeks apart, depending on how many veins are treated and their size. Larger veins sometimes need repeat injections to close completely. Your vein specialist can estimate the number after examining your legs.
Can I exercise after sclerotherapy?
Walking is encouraged the same day and every day afterward. Most people avoid heavy leg workouts, running and heavy lifting for a few days to about a week. Ask your provider for guidance based on the size of the veins treated.
Will the brown marks after sclerotherapy go away?
Brown staining along treated veins comes from iron released as trapped blood breaks down. It usually lightens gradually over several months, and in most people it fades. Avoiding sun on treated areas and having trapped blood released can help.
Is sclerotherapy covered by insurance?
Treatment of spider veins for cosmetic reasons is usually not covered. Sclerotherapy of symptomatic varicose veins after documented reflux on ultrasound may be covered by many insurance plans, including Medicare, when it is medically necessary.
How long do I need to wear compression after sclerotherapy?
It varies with the size of the veins treated, but many patients wear stockings for several days up to about two weeks. Compression helps the vein walls stay together and reduces bruising and trapped blood.
Is sclerotherapy painful?
Most patients describe a brief sting or mild burning with each injection, because the needles used are very fine. No anesthesia is usually needed, and a typical session takes about 15 to 45 minutes. Any soreness afterward is usually mild and short-lived.
Trusted Health Resources
- Chronic Venous Insufficiency, Society for Vascular Surgery
- Venous Insufficiency, MedlinePlus Medical Encyclopedia (NIH)
- Varicose Veins and Spider Veins, MedlinePlus (NIH)