American Society of Hirudotherapy
Medicinal Leech Therapy: Patient Handout
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Medicinal leech therapy is FDA-cleared for venous congestion in surgical grafts, flaps, and replants. It is delivered by a licensed clinician in a clinical setting. Read this handout before your appointment and ask your clinician any questions it raises.
Not for home use
Medicinal leech therapy must be administered by a trained, licensed clinician under sterile conditions with monitoring. Self-application carries serious risks including uncontrolled bleeding, infection (particularly <em>Aeromonas hydrophila</em>), and improper attachment. Do not attempt at home.
Contraindications
Tell your clinician if any of the following apply to you. Some conditions absolutely rule out treatment; others require caution and additional monitoring.
Absolute (do not treat)
- Hemophilia or other significant bleeding disorder
- Active anticoagulation that cannot be safely paused
- Severe anemia (Hb < 8 g/dL)
- Known allergy to leech proteins or hirudin
- Severe peripheral arterial disease at the treatment site
- Active local or systemic infection
- Pregnancy (first and third trimester)
Relative (caution required)
- Immunocompromised state (cancer, HIV, transplant, biologics)
- Diabetes mellitus with peripheral neuropathy
- Concurrent NSAIDs or aspirin
- Phobia of leeches or significant anxiety
- Recent dental, surgical, or invasive procedure
- Chronic skin conditions at the proposed site
Before your session
- Eat a light meal 1–2 hours before; avoid alcohol for 24 hours.
- Do not take aspirin or NSAIDs in the 48 hours prior unless your physician has approved it.
- Bring a list of all medications, supplements, and allergies.
- Arrange transportation home in case you feel light-headed afterward.
- Wear loose clothing that exposes the treatment area.
During treatment
- Initial bite is brief; most patients report a pain score of 1–2 out of 10 (a small pinch). Sensation is significantly reduced after attachment.
- Each leech feeds for 30–60 minutes and detaches on its own. Do not pull a leech off.
- Slight oozing of blood is expected for several hours after detachment — this is therapeutic, not a complication.
- Tell your clinician immediately if you feel faint, nauseated, or light-headed.
After treatment
- Keep the treated area clean and dry for 24 hours.
- Take prophylactic antibiotic exactly as prescribed (typically a fluoroquinolone) to prevent Aeromonas infection.
- Apply a clean dressing if oozing continues; change as instructed.
- Avoid heavy lifting, hot baths, and alcohol for 24 hours.
- Plan for someone to drive you home if you feel light-headed.
Seek medical help
Most after-effects are mild. Contact your clinician or seek emergency care if you experience any of the following:
- Bleeding that soaks through dressings, does not slow with 10–15 minutes of firm pressure, or pulses or spurts (arterial pattern)
- Lightheadedness, fainting, severe dizziness, or shortness of breath
- Spreading redness, warmth, or pus at the treatment site
- Fever above 100.4°F (38°C) or chills
- Severe pain at the site or radiating from it
- Signs of allergic reaction (hives, swelling, difficulty breathing)
Emergency: call 911 or your local emergency number immediately.