sclerotherapy: Definition, Uses, and Clinical Overview

Definition (What it is) of sclerotherapy

sclerotherapy is a minimally invasive procedure that treats certain veins or vascular lesions by injecting a medication (a “sclerosant”) into the target vessel.
The injected agent irritates the vessel lining so the vein closes and is gradually replaced by scar-like tissue.
It is commonly used in cosmetic medicine for spider veins and small varicose veins, and in reconstructive/vascular care for selected venous or lymphatic malformations.
The exact technique and sclerosant used vary by clinician, indication, and local regulatory approvals.

Why sclerotherapy used (Purpose / benefits)

sclerotherapy is used to reduce the visibility and/or symptoms of unwanted superficial veins and some low-flow vascular lesions. In cosmetic contexts, the goal is usually to improve the appearance of spider veins (telangiectasias) and small reticular veins—most often on the legs—where patients may be bothered by discoloration, branching patterns, or asymmetry.

In medical and reconstructive contexts, clinicians may use sclerotherapy to help control symptoms from certain vascular malformations (for example, discomfort, localized swelling, or functional interference), or to reduce lesion size as part of a broader treatment plan. It can also be used to manage recurrent or residual veins after other venous procedures, depending on anatomy and the source of venous reflux.

Potential benefits, in general terms, include:

• A minimally invasive approach that is often performed in an outpatient setting
• Targeted treatment of specific visible veins or lesion components
• The ability to stage treatment over multiple sessions when needed
• Cosmetic improvement that can be meaningful for patient confidence and clothing choices
• Symptom relief in selected cases (for example, aching or heaviness associated with superficial venous disease), depending on the underlying cause

Results and durability vary by anatomy, the underlying venous problem (if present), technique, and clinician.

Indications (When clinicians use it)

Common scenarios where clinicians may consider sclerotherapy include:

• Spider veins (telangiectasias), especially on the legs
• Reticular veins (small, bluish superficial veins often feeding spider veins)
• Selected small varicose veins, sometimes with ultrasound guidance
• Residual or recurrent superficial veins after other vein treatments (varies by case)
• Symptomatic superficial venous disease in appropriately selected patients (evaluation differs by practice)
• Certain low-flow venous malformations as part of multidisciplinary care (often staged)
• Certain lymphatic malformations in specialized settings (agent choice and technique vary)
• Patients seeking cosmetic improvement where noninvasive options have limited effect

Contraindications / when it’s NOT ideal

sclerotherapy may be unsuitable or deferred in situations such as:

• Known allergy or hypersensitivity to the planned sclerosant or its components
• Acute deep vein thrombosis (DVT), significant active clotting disorders, or high thromboembolic risk (selection varies)
• Local skin infection, cellulitis, or significant inflammation at/near planned injection sites
• Severe peripheral arterial disease or markedly impaired limb circulation (assessment varies)
• Pregnancy (often deferred) and, in some practices, early breastfeeding (approaches vary by clinician and local guidance)
• Inability to ambulate or comply with post-procedure instructions that reduce stasis (plans vary by case)
• Large, untreated sources of venous reflux (for example, major saphenous insufficiency) when a different primary treatment may be needed first
• Certain cardiac conditions or right-to-left shunts may be relevant particularly for foam techniques (screening practices vary)
• Patients expecting a single-session, permanent removal of all veins (realistic expectations are important)

In some cases, another approach—such as endovenous ablation, phlebectomy, laser/light devices, or observation—may be more appropriate depending on anatomy and goals.

How sclerotherapy works (Technique / mechanism)

sclerotherapy is minimally invasive, not a traditional surgical procedure. It does not rely on incisions, sutures, implants, or tissue removal in the way many cosmetic surgeries do.

Primary mechanism: a sclerosant is injected into the target vein or lesion. The agent irritates and damages the inner lining (endothelium), leading to closure of the vessel and, over time, remodeling into fibrous tissue. Blood flow is redirected to healthier veins, and the treated superficial vessel becomes less visible.

Typical tools/modalities used:

• Very small needles or microcatheters for injection
• Liquid sclerosant or foam sclerosant (foam displaces blood and increases contact with the vein wall in many cases)
• Ultrasound guidance for deeper, non-visible, or larger veins and for some malformations (often called ultrasound-guided sclerotherapy)
• Vein visualization aids in some offices (lighting, transillumination, or similar)
• Compression garments or wraps may be used after treatment, depending on clinician preference and the vein type

Because sclerotherapy targets vessel closure rather than “tightening” skin or “restoring volume,” it is distinct from aesthetic injectables (fillers) and energy-based skin devices, even though all may be performed in outpatient settings.

sclerotherapy Procedure overview (How it’s performed)

A typical workflow for sclerotherapy is straightforward, but details vary by indication (cosmetic leg veins vs vascular malformations), vein size, and whether ultrasound guidance is used.

1. Consultation
   The clinician reviews concerns (appearance and/or symptoms), medical history, medications, prior vein treatments, and risk factors. Expectations are discussed, including the likelihood of multiple sessions and gradual improvement rather than instant clearing.

2. Assessment / planning
   The legs or target area are examined. Some patients undergo venous evaluation (often ultrasound) to look for deeper venous reflux or anatomy that could influence results. A treatment plan is mapped: which veins to target, the technique (liquid vs foam), and session scheduling.

3. Prep / anesthesia
   The skin is cleansed. Most cosmetic sclerotherapy is performed without general anesthesia; discomfort is usually managed with small needles, technique, and local measures. If treating complex malformations, anesthesia planning may differ by facility and case complexity.

4. Procedure
   The sclerosant is injected into the selected veins/lesion compartments. The clinician monitors for proper placement and response; ultrasound may be used to confirm flow patterns and target location. Multiple injections may be performed in one session within safe dosing limits set by product labeling and clinician judgment.

5. Closure / dressing
   There are typically no incisions to close. Small puncture sites may be covered with simple dressings. Compression may be applied depending on the vein type, area treated, and clinician protocol.

6. Recovery
   Patients generally leave the office the same day. Follow-up may be scheduled to assess response, plan additional sessions, and evaluate for side effects such as pigmentation changes or small trapped blood (which some clinicians may manage with office-based techniques).

Types / variations

sclerotherapy is often described by the form of the sclerosant, the guidance method, and the clinical target.

Common variations include:

• Liquid sclerotherapy (surface veins)
  Often used for smaller spider veins and some reticular veins. Agent choice varies by country and clinician.

• Foam sclerotherapy
  A foamed sclerosant can improve contact with the vessel wall and is often used for larger superficial veins or selected varicose veins. Foam techniques may be performed with or without ultrasound, depending on depth and visibility.

• Ultrasound-guided sclerotherapy
  Used when veins are not easily visible, are deeper, or when treating certain varicose veins and malformations. Ultrasound helps with targeting and monitoring flow.

• Cosmetic telangiectasia-focused treatment vs medical malformation-focused treatment
  Treating spider veins on the legs is typically office-based. Treating venous/lymphatic malformations may be part of specialized, staged care and can involve different agents, imaging, and settings.

• Anesthesia choices
  Many cosmetic cases use no anesthesia or only local measures. Sedation or general anesthesia is not typical for routine spider vein treatment but may be considered for more extensive or painful treatments in other indications. This varies by clinician and facility.

• Adjunctive planning based on venous reflux
  In patients with underlying reflux, clinicians may prioritize treatment of larger refluxing trunks (with other modalities) before or alongside sclerotherapy of surface veins. The sequence varies by case.

Pros and cons of sclerotherapy

Pros:

• Minimally invasive approach with no surgical incisions
• Typically performed as an outpatient procedure
• Targeted treatment for specific veins or lesion components
• Can be repeated or staged across sessions to refine results
• Often compatible with a return to many daily activities relatively quickly (timing varies)
• Useful across cosmetic and reconstructive/vascular indications in selected patients

Cons:

• Often requires multiple sessions for cosmetic goals, especially with widespread spider veins
• Results are gradual; the treated veins may change appearance over weeks
• Side effects such as temporary bruising, swelling, tenderness, or itching can occur
• Pigment changes (brown staining) or “matting” (fine new surface vessels) may occur in some patients
• Less suitable if the main problem is deeper venous reflux that requires a different primary treatment
• Rare but important complications can include skin injury/ulceration, allergic reactions, visual symptoms (more often discussed with foam), or thrombotic events; risk varies by technique and patient factors

Aftercare & longevity

Aftercare and longevity depend on the type of veins treated, the sclerosant used, clinician technique, and individual factors such as vein health and skin response.

What recovery commonly involves (general, non-prescriptive):

• Some clinicians use compression garments or wraps to support vein closure and reduce bruising; practices vary.
• Activity guidance often focuses on maintaining normal circulation and avoiding prolonged immobility, but specifics differ by clinician and patient risk profile.
• The treated area may look bruised or darker before it improves; timing varies by vein size and skin type.
• Follow-up visits may be used to assess response, plan additional sessions, or manage trapped blood in treated veins (when present).

Longevity considerations:

• Treated veins that successfully close often remain less visible, but new veins can develop over time, especially if underlying venous reflux, hormonal influences, or genetic predisposition are present.
• Sun exposure and skin type can influence how noticeable pigmentation changes are and how long they take to fade.
• Lifestyle factors (such as prolonged standing, weight changes, and smoking) may affect venous health and recurrence risk; the degree of impact varies by individual.
• Many patients treat sclerotherapy as a process: initial clearing followed by periodic maintenance if new spider veins appear.

Alternatives / comparisons

The “best” alternative depends on the vein type (tiny spider veins vs larger varicose veins), whether there is underlying reflux, symptoms, and patient preferences.

Common comparisons include:

• sclerotherapy vs laser/light treatments (e.g., vascular lasers or IPL)
  Laser/light devices can target small superficial vessels through the skin without injections, which some patients prefer. They may be useful for certain tiny vessels or for patients who cannot have injections in a specific area. However, for many leg spider veins and reticular veins, injections are often used because they can treat a broader network; response varies by vessel size, depth, and device.

• sclerotherapy vs endovenous ablation (thermal or non-thermal)
  Endovenous ablation (such as radiofrequency or laser ablation, or other closure methods) is typically aimed at larger refluxing trunk veins (for example, saphenous veins). sclerotherapy is often used for smaller surface veins or as an adjunct after reflux is addressed. These approaches may be complementary rather than direct substitutes.

• sclerotherapy vs ambulatory phlebectomy
  Phlebectomy removes bulging surface varicose veins through tiny punctures. It is more “procedural” than injection therapy and may be chosen for large, rope-like veins. sclerotherapy may be preferred for smaller veins, diffuse networks, or finishing work after other treatments.

• sclerotherapy vs conservative management
  Compression, activity modification, and symptom management do not remove veins but may help symptoms for some patients. People may choose conservative care when cosmetic change is not the priority or when procedural risks outweigh benefits.

• sclerotherapy vs observation for malformations
  For venous/lymphatic malformations, observation, surgery, embolization, or combined approaches may be considered depending on lesion type, location, and symptoms. sclerotherapy can be one tool among several in multidisciplinary care.

Common questions (FAQ) of sclerotherapy

Q: Is sclerotherapy painful?
Most patients describe brief stinging, burning, or pressure during injections rather than significant pain. Discomfort varies with vein size, location, and the sclerosant used. Some areas can be more sensitive than others.

Q: How many sessions are usually needed?
Many people need more than one session, especially for extensive spider veins or mixed vein patterns. The number of treatments depends on how many veins are present, how they respond, and whether underlying reflux is contributing. Treatment planning is individualized.

Q: How long does it take to see results?
Changes are usually gradual. Smaller veins may fade over weeks, while larger veins can take longer to flatten and lighten. Bruising or temporary darkening can occur before improvement is noticeable.

Q: Will sclerotherapy leave scars?
Because sclerotherapy uses tiny needle punctures rather than incisions, scarring is not typical. That said, skin color changes, small marks, or localized texture changes can occur in some cases. Healing appearance varies by skin type and reaction.

Q: What are common side effects and risks?
Common temporary effects include redness, swelling, bruising, tenderness, and itching. Other recognized issues include brown discoloration (hyperpigmentation), “matting” (fine new vessels), or small firm lumps from treated veins. Rare but serious complications—such as skin ulceration, allergic reactions, or clot-related events—are discussed during informed consent, with risk varying by patient factors and technique.

Q: Is anesthesia required?
General anesthesia is not typically used for routine cosmetic sclerotherapy of spider veins. The procedure is commonly done without anesthesia or with simple comfort measures, depending on the clinician. More complex cases (such as certain malformations) may involve different anesthesia planning.

Q: What is the downtime after sclerotherapy?
Many patients resume normal daily activities relatively quickly, but short-term bruising and tenderness can affect comfort and clothing choices. Clinicians often provide activity and compression instructions that may influence routines for a period of time. Downtime is best understood as “variable,” not one-size-fits-all.

Q: How long do the results last?
If a vein closes successfully, it often remains less visible, but the body can develop new spider veins over time. Longevity depends on genetics, hormones, vein health, underlying reflux, and lifestyle factors. Some patients pursue periodic maintenance treatments.

Q: Is sclerotherapy safe?
When performed by trained clinicians with appropriate patient selection and dosing, sclerotherapy is widely used in medical practice. No procedure is risk-free, and safety depends on factors such as medical history, vein anatomy, sclerosant choice, and technique. Patients are typically screened for risk factors and counseled on warning signs to watch for.

Q: What affects the cost of sclerotherapy?
Cost varies by clinician and case. Key drivers include the number of sessions needed, whether ultrasound guidance is used, the complexity of the vein pattern, geographic region, and whether treatment is cosmetic or medically indicated within a broader venous care plan. Clinic pricing structures also differ.