leg vein sclerotherapy · bruising · lumps · pigmentation changes · follow-up after treatment
Bruising, tenderness, areas of firmness and pigmentation changes may occur after sclerotherapy. Complications are also possible, including thrombosis, skin damage and an allergic reaction. A medical assessment determines whether a symptom is an expected reaction or requires treatment. [1–3]
This article covers sclerotherapy of the leg veins using a liquid or foam sclerosant. We explain what to report to your doctor and when urgent help is needed.
Author: Dr Arthur Abbazov – phlebologist.
Medical review: Dr Piotr Rak, PhD.
Key information at a glance
- The appearance of the legs changes gradually. Bruising and palpable lumps can make it harder to assess the result early on.
- Not every lump means deep vein thrombosis. However, its cause cannot be diagnosed from a photograph alone.
- Severe or worsening pain and new swelling require urgent assessment. Do not wait for your scheduled follow-up appointment.
- Shortness of breath, signs of a stroke or a severe allergic reaction require immediate help. Call 112 or 999.
What reactions may occur after sclerotherapy?
The medication injected into the vein causes a reaction in its wall, leading to closure of the vessel. Remodelling of the treated vein and changes in the skin's appearance take time. You may notice:
- bruising and small marks at injection sites;
- tenderness, a brief burning sensation or local soreness;
- firmer sections of the vein and palpable lumps;
- brownish pigmentation over the treated vessel.
Lumps may take weeks to settle, while pigmentation can take months to fade. Some pigmentation changes persist for longer or remain permanent. There is no single date by which all marks can be promised to disappear. [1–3]
Another possible change is matting, a network of new, tiny blood vessels around the treated area. This should be assessed, particularly if it persists or bothers the patient. [2, 4]
Which sclerotherapy complications are discussed before treatment?
A quotation from a medical publication
“If correctly executed, sclerotherapy is an efficient form of treatment with few complications.”
Your doctor assesses your individual risk of complications before determining whether treatment is appropriate.
A reaction within the vein being closed is not the same as deep vein thrombosis. However, possible complications include superficial vein thrombosis, a marked inflammatory reaction and deep vein thrombosis. Distinguishing between them may require a clinical examination and ultrasound. [3, 4]
Skin damage, ulceration or necrosis around the treated area, scarring, infection at an injection site and an allergic reaction to the medication are also possible. Nerve damage or altered sensation have rarely been reported. [1, 3, 4]
Rare serious events include pulmonary embolism, a severe allergic reaction and neurological events. The risk depends on the patient's condition, the type of vessels, the medication used and the extent of treatment. No single percentage describes the risk for all sclerotherapy procedures. [2–4]
Visual disturbances and migraine after foam sclerotherapy
Transient visual disturbances and migraine-like symptoms have been reported after foam injections, more often in people with a history of these symptoms. Report every new symptom to the team immediately. Do not assume on your own that it is just a migraine or a harmless reaction to the procedure. [2, 3, 5]
Sudden loss of vision, speech difficulties or weakness on one side of the body require emergency help even if the symptoms resolve. [7]
Symptoms after sclerotherapy – when is assessment needed?
| What have you noticed? | What should you do? |
|---|---|
| Minor bruising or tenderness that is improving | Follow the recommendations and monitor your recovery. Report symptoms if they are unusual, worsen or cause concern. |
| A persistent lump, pigmentation or tiny visible vessels | Discuss these at your follow-up appointment. Seek assessment sooner if significant pain, swelling or redness develops. |
| A blister, wound, darkening skin or spreading redness | Contact a doctor urgently. Do not try to treat the area by puncturing or squeezing it yourself. |
| New or worsening pain and swelling in one leg | Seek urgent medical assessment. If thrombosis is suspected, do not wait for a routine follow-up appointment. |
The time symptoms started, their severity and how they change over time also matter. [1–3, 5, 6]
When should you call 112 or 999 for help?
Immediate help is particularly important for:
- sudden shortness of breath, chest pain or fainting;
- swelling of the tongue or throat, difficulty breathing or swallowing;
- drooping on one side of the mouth, weakness on one side of the body, speech difficulties or sudden loss of vision.
Do not wait for the reception team to respond or for a scheduled appointment. Do not drive yourself. Neurological symptoms require urgent help even after they have resolved. [6–8]
What should you do about a lump, and what does follow-up after sclerotherapy involve?
Do not puncture or squeeze lumps. Do not try to remove the contents of a treated vein yourself, and do not vigorously massage a painful area unless advised to do so. Your doctor will assess whether observation is sufficient or further treatment is needed.
Follow-up includes assessing your symptoms and the treated areas. Ultrasound may be needed depending on the veins involved, symptoms and risk. Your doctor determines the timing and extent of follow-up; new concerning symptoms are a reason for earlier assessment. [1, 4]
When contacting the clinic, provide the date and extent of the procedure, the location of the symptom, when it started and whether it is getting worse. A photograph may help the discussion but cannot replace an examination.
Follow the recommendations on activity, compression and medication. Compression is discussed in the article compression stockings after EVLA and sclerotherapy. Do not stop prescribed anticoagulants on your own.
How is risk assessed before treatment?
Tell your doctor about previous thrombosis, diagnosed thrombophilia, medication allergies, migraine with aura and symptoms after previous sclerotherapy. Current medication, pregnancy and reduced mobility are also important. [1, 3, 4]
Your doctor assesses the indications, venous anatomy, contraindications and any tests needed. Assessment and following recommendations help determine appropriate care but do not eliminate all risk.
If sclerotherapy complements laser treatment, the plan includes both methods. Read about combined laser treatment and sclerotherapy for varicose veins and find out about assessment for laser treatment of leg varicose veins.
Frequently asked questions about sclerotherapy complications
Does bruising after sclerotherapy mean there is a complication?
Bruising can occur after injections. If it is accompanied by worsening pain, significant swelling or other new symptoms, earlier assessment is needed.
Does a hard lump mean thrombosis?
A lump may involve the vein being closed. However, feeling the area or looking at a photograph alone cannot rule out thrombosis or assess the whole venous system.
Do pigmentation changes always disappear?
No. They may gradually fade over months, but some persist for longer or permanently. Persistent changes should be discussed at follow-up.
Can sclerotherapy cause deep vein thrombosis?
Yes, this is a possible complication. New or worsening pain and swelling in one leg require urgent assessment, while shortness of breath or chest pain require immediate help.
What should you do about visual disturbances after a foam injection?
Report them to the team immediately. Sudden loss of vision, or visual symptoms accompanied by speech difficulties or limb weakness, require emergency help even if they resolve.
Can you puncture or squeeze a lump yourself?
No. This can damage the skin and cause infection. Your doctor decides how to manage a painful lump after assessing it.
Does another session mean the previous treatment failed?
Not always. An additional stage may address previously untreated veins or follow an assessment of the result. A remaining vein and a complication are different situations that need to be discussed.
These answers are based on the sources listed below. [1–7]
Discuss the benefits and risks of varicose vein treatment in Gdańsk
If you are considering treatment for varicose veins of the legs, start with a consultation. At Wyspa Medycyny Przyjaznej, Dr Arthur Abbazov assesses patients for treatment. A consultation and Doppler ultrasound of the leg veins are required before EVLA. Additional sclerotherapy is selected according to the indications.
At your appointment, discuss your individual risk, recommendations and how to obtain help after the procedure. If you have a problem after treatment already performed, contact the clinic that carried it out.
Wyspa Medycyny Przyjaznej, 15 Toruńska Street, Gdańsk. Warning symptoms require urgent help regardless of reception availability.
Medical sources
- RadiologyInfo (ACR/RSNA) – sclerotherapy and possible side effects.
- Gloucestershire Hospitals NHS – foam sclerotherapy and its risks.
- Cambridge University Hospitals – foam sclerotherapy for leg varicose veins.
- Rabe et al. – published DGP guidelines on sclerotherapy (2020/2021).
- University Hospitals Sussex – what to expect and complications after foam sclerotherapy.
- NHS – symptoms of deep vein thrombosis.
- NHS – stroke symptoms and emergency help.
- NHS – symptoms of a severe allergic reaction.
This article is for information purposes. It is not intended to diagnose complications from a description or photograph and does not replace individual recommendations after treatment.