Sclerotherapy: Everything You Need to Know

Sclerotherapy is a non-surgical procedure used to treat varicose veins and spider veins. It involves the injection of a special solution called a sclerosant into the veins to seal them off. This forces blood to reroute itself to healthier veins. In addition to reducing the appearance of varicose and spider veins, sclerotherapy is sometimes used to treat malformed lymph vessels, hemorrhoids, and hydroceles (the swelling of the scrotum).

recovering from sclerotherapy
Illustration by Brianna Gilmartin, Verywell 

What Is Sclerotherapy?

Sclerotherapy (sclero- meaning "hardness" and -therapy meaning "treatment") is an in-office procedure most often used to treat varicose veins (also known as chronic venous insufficiency) and spider veins (telangiectasia). It is one of the least invasive treatment options for these conditions, neither involving anesthesia nor any significant downtime.


Sclerotherapy is generally regarded as safe but is not for everyone. Sclerotherapy is absolutely contraindicated for use in people with the following health conditions:

Each of these conditions are associated with blood clots. The use of a sclerosant can cause a clot to dislodge, triggering severe complications including pulmonary embolism (with DVT) and sudden cardiac arrest (with PE).

Sclerotherapy is also contraindicated in pregnancy, in part because pregnancy can place a woman in a hypercoagulable state. At the same time, pregnancy can lead to the formation of varicose veins, which often shrink or disappear within months of delivering the baby.

People with a known allergy to the sclerosant agent (which include detergents like sodium tetradecyl sulfate and chemical irritants like chromated glycerin) should not be exposed to these agents. There are salt-based alternatives that can be used in their place.

Sclerotherapy should be used with extreme caution in people with untreated diabetes who may experience venous ulceration. People with well-controlled diabetes are not subject to the same concerns.

Possible Risks

Sclerotherapy does carry certain risks, some of which are superficial and others of which are potentially serious. These include:

  • Permanent hyperpigmentation (darkening) of the treated area
  • Superficial phlebitis (venous inflammation)
  • Venous matting (the development of tiny veins emanating from the site of a sclerosed vein)
  • Pyoderma gangrenosum (an autoimmune reaction leading to the formation of a venous ulcer)
  • Thrombophlebitis (the formation of a venous clot)

Purpose of Sclerotherapy

Sclerotherapy is considered the treatment of choice for spider veins and smaller varicose veins that cannot be managed with compression stockings or weight loss.

The injection of a sclerosant reduces the appearance of these superficial red or purplish veins in slightly different ways:

  • Detergent-based sclerosants disrupt the cellular membrane of a vein, causing walls of the vein to constrict and stick together.
  • Chemical irritants cause the vessel to initially swell, forcing out blood, and then collapse as the caustic agent damages the lining of the vein.
  • Osmotic sclerosants comprised of sodium chloride (salt) draw water out of the lining of a vein, flushing out blood and causing the dehydrated vessel to collapse.

In addition to reducing the appearance of spider and varicose veins, sclerotherapy can alleviate pain, aches, cramps, and burning sensations that often accompany them.

Sclerotherapy can be used to treat spider veins on the face, including those on the cheek or around the edges of the nose. Even so, it is a delicate procedure and one that can cause permanent scarring if not performed by a highly skilled and experienced dermatologist.

Pre-Treatment Evaluation

Prior to the procedure, the doctor will perform a physical examination to ensure that you have no health conditions that contraindicate treatment. An ultrasound may also be used to establish the depth and direction of larger varicose veins in order to map out the procedure.

These evaluations can help estimate how many treatments are needed to achieve the desired effect. Spider veins may only require a single treatment, while moderate-sized varicose veins may require several.

Large varicose veins—including so-called trunk veins that are thick, long, and knobbly—may not respond well to sclerotherapy or leave behind a visible dent after treatment. These are often more effectively treated with surgery (sometimes referred to as "venous stripping").

Other Uses

Sclerotherapy can be used to treat other conditions characterized by venous swelling or the abnormal accumulation of fluids in tissues. Among them:

  • Lymph vessel malformations (the benign clumping of the vessels that carry lymph fluid) can be treated with sclerotherapy as an alternative to surgical ablation or surgical drainage.
  • Hemorrhoids can be treated with sclerotherapy, although the treatment can be less effective than rubber band ligation in treating larger, high-grade hemorrhoids.
  • Hydroceles (the swelling of the scrotum caused when fluids collect in the sheath surrounding the testicle) is sometimes treated with sclerotherapy when the condition is persistent but not severe enough to require surgery.

How to Prepare

Even though sclerotherapy is considered minimally invasive, that shouldn't suggest that it is a walk-in procedure. Once the treatment sessions are scheduled, your doctor will provide you a list of things you need to do and avoid. By following these instructions carefully, you are more likely to achieve the desired results.


Sclerotherapy is an outpatient procedure performed in a doctor's office. Varicose veins and spider veins are usually treated by a dermatologist, while lymph vessel malformation, hemorrhoids, and hydroceles may be treated by a vascular radiologist, gastroenterologist, or urologist, respectively.

What to Wear

Depending on where the veins are located, you will need to wear clothes that you can either remove or don't get in the way of the procedure. Since sclerotherapy is typically performed on the legs, you may want to wear loose-fitting shorts. Many doctors will provide a pair of disposable shorts, called exam shorts, to change into.

Food and Drink

There are no food or drink restrictions required for sclerotherapy. You can eat breakfast or lunch as you normally would before arriving.


Do not take nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, Advil (ibuprofen), Aleve (naproxen), or Celebrex (celecoxib) 48 hours before and after sclerotherapy. These drugs can promote bleeding, slow healing, and increase the risk of scarring.

You may also need to avoid tetracycline antibiotics and corticosteroids like prednisone. Tetracycline may promote hyperpigmentation, while prednisone can alter the effectiveness of the sclerosant.

What to Bring

Be sure to bring your driver's license (or other form of government ID) as well as your insurance card to check-in to your appointment. If upfront payment is required for copay or coinsurance, call beforehand to find which forms of payment they accept.

Your doctor will ask you to bring a pair of compression socks or stockings to wear after the procedure. Purchase them well in advance, and wear them three to four days beforehand to ensure a snug but comfortable fit.

What to Expect on the Day of the Procedure

On the morning of the sclerotherapy session, do not shave or apply lotion, moisturizer, oil, or ointments of any sort to your legs. The same applies to other parts of the body.

Before the Treatment

After you've checked in and have signed the necessary consent forms, you will be led to a treatment room to change into the exam shorts, if provided. Photographs of your legs will then be taken for "before and after" comparisons during follow-up visits.

During the Treatment

To start the procedure, you will lie down on the examination table. If the area to be treated is your legs, you may be asked to raise a little. Pillows and bolsters may be provided. The treatment area will then be cleansed with alcohol or some other antiseptic solution.

The sclerosing agent will then be injected into a vein with a very fine needle (usually between 30 and 33 gauge). Needles this small usually don't cause overt pain, but there may be some discomfort. Some veins may require multiple injections. The doctor will then massage the surrounding tissue to help disperse the solution along the route of the vein.

Smaller veins are treated with liquid sclerosing solutions. Larger ones may require a foam sclerosant, which has the same effect but requires smaller doses than what would be needed with the liquid formulation.

If the treated area is small, you may only require one treatment. If additional treatments are needed, doctors will usually wait several weeks between treatment to allow for proper healing.

Sclerotherapy sessions take between 15 and 45 minutes, depending on how extensive the treatment area is.

After the Treatment

Once completed, you can change into your clothes and immediately put on the compression socks or stockings. Most people do not feel any pain or discomfort and can drive themselves home. With that said, if the treatment area is extensive, you may want to play it safe and ask a friend or family member to drive instead.


It is not uncommon to experience redness, swelling, warmth, or itching around the injection site for a couple of days after sclerotherapy. This is normal and will usually resolve on its own without treatment. If needed, you can take Tylenol (acetaminophen) to help relieve inflammation and discomfort. Elevating your legs also helps. Bruising is uncommon but can occur.

The one thing you must do is wear your compression socks during recovery, particularly when you are on your feet. You will need to do so for seven to 14 days, depending on the extensiveness of the treatment. You do not need to wear them at night while you sleep.

In addition:

  • Do not take hot baths or sit in a hot tub or sauna. Instead, take shorter and cooler showers than normal.
  • Do not apply heated pads or any form of heat to the injection sites as this can promote inflammation and bleeding.
  • Walk at least 30 minutes a day at a slow to moderate pace for the first two weeks.
  • Avoid heavy lifting or strenuous exercise for the first two weeks.
  • Avoid direct sunlight or suntan beds as this can lead to hyperpigmentation.

After two weeks, you may feel tiny lumps in the treated area. This is caused when blood becomes trapped under the skin and is completely normal. The lumps usually dissipate over time, although it can sometimes take months. If it doesn't resolve, tell your doctor as the lump may require drainage.

The same applies to the formation of new blood vessels around the injection site (referred to a venous matting). Tell your doctor as these can be treated with additional sclerotherapy or laser skin therapy.

When to Call a Doctor

Call your doctor immediately if you experience any of the following after sclerotherapy:

  • Dizziness or fainting
  • Visual disturbances
  • Rash or hives
  • Difficulty breathing
  • Chest pain
  • Nausea or vomiting
  • Severe leg pain
  • Severe swelling of one leg
  • Coughing up blood

These could be signs of a rare but serious complication, such as allergy, thrombophlebitis, DVT, or PE.

Long-Term Care

Your doctor will schedule a post-treatment assessment once the overall procedure is completed. For spider veins and smaller varicose veins, appointments may be scheduled six to eight weeks later. For larger varicose veins, your doctor may wait three to four months.

The efficacy of treatment is measured not only by the "before and after" photos but also by the alleviation of any pain or cramping you may have experienced.

Once a spider or varicose vein has been completely resolved, it is unlikely to recur. If the problem persists, you may need to explore other treatments, including vascular stripping, catheter-assisted radiofrequency ablation, or endoscopic vein surgery.

A Word From Verywell

Even if you achieve the desired results with sclerotherapy, you would be well-served to avoid the behaviors that contributed to the problem in the first place. This includes standing for long periods of time, wearing high heels, or being overweight.

By exercising, watching your diet, and regularly resting your legs throughout the day, you can avoid recurrence of this aggravating, albeit common, vascular condition.

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Article Sources
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