It neutralizes the accumulated pitta toxins of blood. leeches are applied on  the affected area of patient. Leeches have tiny rows of teeth. They pierce a person’s skin and insert anticoagulants through their saliva. The leeches are then allowed to extract blood, for 20 to 45 minutes at a time.

Enzymes in saliva of leeach (Hirudin) enter the blood which acts as an anti-coagulant. This leech enzyme stays in the blood and do vasodilation and increases the blood supply to the surrounding tissue. This prevent necrosis and expedites the healing.