If you are a trekker, you may have had your encounter with leeches. You look down and see this slimy creature glued to your legs and some drops of blood. If you are a seasoned camper, you will take out some salt or turmeric powder and dust it on the leech and it drops off. A similar leech called Hirudo medicinalis is used in ayurveda for blood-letting. The procedure using the leech is called jalouka avacharana. Earlier, whenever anyone mentioned leech therapy, I would put it in the category of ‘story telling’. I did not quite believe that there was a systematic therapy and science behind it.
In ayurveda, jalouka avacharana has been explained by Sushruta in the sixth century BCE. Since jala (water) is their life, the leeches were called jalouka. Vaghbhata explained that leeches could be used to painlessly let out blood from affected areas. In ayurveda, it is used in diseases of pitta and raktha. In today’s world where diabetes is on the rise and diabetic ulcers are a severe consequence, blood-letting by leeches comes in very handy.
In ancient classics, leeches were divided into nirvisha and savisha types—poisonous and non-poisonous. Only the select non-poisonous types, which were properly identified were used in treatment. Today the leech that is often used for therapy is Hirudo medicinalis. It is olive green in colour with a yellow border.
So, how does one go about a leech therapy? Normally an ayurvedic physician would store these leeches in water in a mud pot. They stay alive for months together in water waiting for their next blood meal. Fresh water streams in Kerala and Karnataka are good places to source these leeches.
After putting on a pair of gloves, the leeches are fished out of the pot and put into a container of water in which turmeric water is dissolved. The leech is cleansed in this water. It normally throws up some saliva. Once the water coagulates, it is time to transfer the leech into another container of fresh water. Only non-chlorinated water is to be used. Once the leech has been thoroughly washed, it is time to deploy it.
The leech is applied to the area from where blood has to be removed. It attaches itself with its rear end and starts searching with its anterior end for a good spot to start sucking blood. Some physicians use a sterilised needle to make a small puncture to draw blood. The leech is attracted to the blood and attaches itself to the skin and starts sucking. Some physicians place their palms on the leech and encourage it to start sucking. The leech is quite small when it is first attached to the skin.
Slowly it bloats in size by sucking the blood. It is fascinating to see the movement of blood through the body of the leech. Once the leech has had its fill, normally about 10-15 ml of blood, it detaches itself automatically. Sometimes a little turmeric is applied near the mouth of the leech encouraging it to let go. Once the leech is detached, the leech’s mouth is covered with turmeric and the blood is slowly milked out. Once the entire blood is removed, it is washed in turmeric water and finally in plain water. The leech is then stored in a bottle with airholes and can be used for treating the same patient again. Normally the leech is applied once a week for about five weeks or till the wound heals.
The therapy is effective in cleaning up non-healing wounds because the leech saliva contains vasodilatory substances that help in better blood circulation. It also contains catecholamines which act on nerve terminations, anti-elastase which degrades elastin and helps in healing stubborn skin lesions, bdellin, which has anti-inflammatory properties and hyaluronidase which has antibiotic properties and also helps in diffusion. The leech also has hirudin, which is a powerful anti-coagulant and makes the blood flow. It secretes anaesthetic substances, which make the whole procedure painless. The jalouka avacharana is also an FDA-approved therapy.
The writer is retired Additional Chief Secretary of Tamil Nadu. She can be reached at sheelarani.
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