Leech therapy / Jalaukavacharana is defined as the therapeutic application of living medicinal leech to the skin in order to evacuate blood from a localized area of the body.

Ayurveda and Leech therapy:
In Ayurveda leech or Jaluka is used to expel out impure blood containing dosha.In various classical ayurvedic texts like astanghrudyam Sushruta Samhita, there is a wide description of leech therapy. Acharya Sushruta propounds practical guidelines for bloodletting and claims it as the most effective therapy in half of the body ailments.
Among various methods for bloodletting such as Jalaukavacharana karma, Prachhanna karma and Siravedhana karma. Jalaukaavacharna Karma (Leech therapy) is considered as the ideal method to expel out the vitiated blood safely, quickly, and effectively. Application of medicinal leech reportedly increases blood flow within congested tissue via active feeding and indirectly by passive bleeding from leech bite offer detachment.
Active and passive bleeding are both facilitated by the actions of the different salivary secretions of the leeches such as hirudin-an anticoagulant.

Method of leech application:
Selected leeches should be smeared with paste of mustard and turmeric,then kept in water pot for 48 minutes. Active leech is selected and picked out to keep in separate water pot.

Procedure of Jalaukavacharana:
The patient is made to sit or lie down, affected area is washed with clean water. Then the selected leech is kept over the affected area to bite and suck the blood. And retained with soft, white, moist cotton cloth is kept over it. With the appearance of pricking pain and itching at the site of the bite, it is to understood that leech is sucking pure blood, then it should be removed by sprinkling salt or turmeric powder over its mouth.

Post therapy procedure:
At the site of bite, turmeric is applied to arrest the bleeding.

How to know the leech is biting the affected area?:
when it makes its mouth in the shape of a horse’s hoof, and lifts its neck then it is to be understood as biting, it should be covered with a moist cloth and retained.

What to do if leech does not bite the affected area?:
If it does not bite, a drop of milk or blood is put at its mouth or small incision is made over the affected area. Inspite of all these procedure if it does not bite, then another leech is applied.