Leeches for varicose veins: do they help or cause harm? A doctor’s honest answer

Leeches for varicose veins may briefly reduce heaviness and swelling, but they do not treat the disease. Hirudin in leech saliva slows local blood clotting, so the bite site bleeds for some time. A leech does not eliminate venous reflux, remove an enlarged vein, or replace vein duplex ultrasound and treatment by a phlebologist.

By evening, your legs may feel heavier, veins may become more prominent, and your shoes may feel tighter. In this situation, some people recommend placing a leech directly on a varicose vein: 「The blood will become thinner, and you will feel better.」 Relief is indeed possible, but it is short-lived. The underlying cause remains, while the risk of bleeding and inflammation increases.

I have worked in vascular surgery since 2019 and regularly see the consequences of treating veins based on advice from the internet or acquaintances. I do not dismiss hirudotherapy: this method has an understandable mechanism of action. However, it should not be confused with comprehensive treatment for varicose veins.

What hirudin actually does

The saliva of a medicinal leech contains hirudin and other biologically active substances. Hirudin interferes with the action of thrombin, one of the key enzymes involved in blood clotting. As a result, blood at the bite site clots more slowly.

Possible short-term effects:

• the bite site bleeds for longer;
• local tissue tension may decrease;
• swelling may sometimes become less pronounced;
• the sensation of heaviness may temporarily ease;
• the skin around the bite may itch, become red, or feel sensitive.

This effect is local and temporary. It does not mean that the blood throughout the body has become 「thinner」 or that the varicose veins have disappeared.

With varicose veins, the problem is usually related to impaired venous valve function and backward blood flow, known as reflux. A leech does not restore the valve or stop the abnormal flow. It also does not remove the vein or dissolve a varicose vein.

Therefore, after temporary relief, heaviness, swelling, and bulging veins may return. If the cause is not identified, a person loses time and continues affecting an area that may require a different type of treatment.

Why placing a leech on a varicose vein is especially dangerous

An enlarged superficial vein lies close to the skin and may be fragile. A bite injures an area with altered blood flow, where pressure inside the vessel may be elevated.

Main risks:

• prolonged bleeding. Hirudin interferes with clot formation, and a damaged varicose vein may bleed longer than the patient expects;
• infection of the wound. Any bite damages the skin. If it is not treated properly, bacteria may enter the wound;
• worsening local inflammation. If there is already a painful, firm area, redness, or skin tension nearby, additional trauma may worsen the condition;
• an allergic reaction. Marked itching, swelling, hives, and other reactions are possible;
• bruising and skin irritation. The marks may last longer than desired;
• an inappropriate treatment choice. While a person repeats the procedures, no vein duplex ultrasound is performed and the cause of the symptoms remains unclear.

It is especially unsafe to place a leech on an area that is painful, red, hot, or hardened. The condition of a vein cannot be reliably determined through messages or by appearance alone. These symptoms require an in-person examination.

A leech does not 「draw bad blood」 from the vein. It leaves a wound in the skin and introduces substances that slow local blood clotting.

Leeches or treating the cause: what changes

The first practical step is vein duplex ultrasound. The examination helps identify the source of reflux, enlarged veins, and signs of inflammation. After that, treatment options can be discussed.

Depending on the situation, EVLA, sclerotherapy, miniphlebectomy, or observation with recommendations on activity and compression may be used. Sclerotherapy is not suitable for every enlarged vein, while laser treatment requires assessment of the vessel anatomy. It is not possible to state the cost accurately in advance: it is determined after the ultrasound examination and specified in a written estimate.

If spider veins are the main concern, this is a separate issue. CLaCS combines a cryolaser and sclerotherapy: the laser acts through the skin, while the sclerosant is injected into the feeding vein. Nothing is 「removed through punctures」—the removal of individual varicose tributaries is part of miniphlebectomy. You can read more about approaches to spider veins in the section spider vein treatment.

How to assess the situation today

Self-checking does not establish a diagnosis, but it can help you prepare for a consultation.

• Examine your legs in good lighting. Note any bulging veins, changes in skin color, redness, wounds, or oozing.
• Compare your legs for swelling. In the evening, check whether one ankle has become noticeably larger than the other. Do not wrap the leg tightly or press on it painfully.
• Record your symptoms. When does the heaviness appear—in the morning or toward evening? Does it improve after walking or resting with your legs elevated? Do you have nighttime cramps?
• Assess the painful area. If it is hot, red, firm, and painful, do not place a leech there or massage the area.
• Photograph any changes. Photos taken in the same lighting can help the doctor assess changes in the skin and swelling, but they do not replace an examination.
• Schedule vein duplex ultrasound if symptoms recur, a vein becomes enlarged, swelling appears, or discomfort interferes with everyday life.

At the consultation, ask the doctor specific questions:

• Where is the source of the venous reflux?
• Are there signs of inflammation in a superficial vein?
• Does the vein need treatment, or is observation sufficient for now?
• Is compression suitable for me, and what type should I use?
• What method is being recommended, and which specific vein is it intended to close or remove?
• What should I do if pain, swelling, or bleeding increases after the procedure?

If you have already used a leech, tell the doctor when and where it was placed, how long the bleeding lasted, and which medications you take. Do not conceal the procedure: this helps assess the risk.

Other everyday questions are also related to the veins in your legs. Restrictions after procedures and in the presence of symptoms differ from advice for ordinary leg fatigue. I discuss activity, massage, and common mistakes in detail in the article Massage for varicose veins: is it allowed or not?.

When to see a doctor urgently

Seek urgent medical attention if the following symptoms appear after a leech or independently of one:

• bleeding that does not stop after prolonged, continuous pressure with a clean cloth;
• rapidly increasing swelling of one leg;
• severe or rapidly worsening pain;
• marked redness and warmth of the skin along the painful area;
• sudden shortness of breath, chest pain, difficulty breathing, or coughing up blood;
• swelling of the face or tongue, difficulty breathing, or widespread hives;
• high fever or pus-like discharge from the wound.

Do not massage the leg, puncture the skin, place another leech, or take medications that affect blood clotting without medical advice. If sudden shortness of breath or chest pain occurs, call emergency services.

Myths that make leeches harmful

Myth: 「If I felt better after the leech, the vein must have started healing.」

Relief may be related to reduced local tension and swelling. It does not prove that the valves have started working normally or that the reflux has stopped.

Myth: 「The leech should be placed directly on the largest vein—this way it will remove the stasis.」

Such an area may bleed longer and be more severely traumatized. Choosing the site by eye does not make the procedure safer.

Myth: 「A medicinal leech completely eliminates the risk of infection.」

Even when medicinal material is used, there remains a risk of skin injury, inflammation, and allergy. Safety depends on the conditions, preparation, skin condition, and monitoring after the procedure.

Myth: 「No other examinations are needed after leech therapy.」

If swelling, heaviness, bulging veins, or pain recur, the cause should be assessed. Symptomatic relief does not replace an ultrasound examination.

Traditional methods should not be dismissed. However, with varicose veins, it is important to distinguish a temporary reduction in symptoms from treatment of the underlying cause. Hirudin affects clotting at the bite site, but it does not close the vein or correct venous reflux.

The practical conclusion is simple: do not place a leech on a varicose vein yourself, especially if it is painful, red, or firm. First undergo an examination and vein duplex ultrasound, then choose a plan: observation, compression, or an appropriate treatment method. If a leech has already been used and prolonged bleeding, increasing pain, swelling, or signs of an allergic reaction occur, seek in-person medical care.

This article is for informational purposes only and does not replace a consultation with a qualified physician. If you are experiencing symptoms, please see a specialist.