Leech therapy, also known as hirudotherapy, is a complementary treatment that uses leeches to treat a variety of conditions: 

• Blood flow: Leeches can improve blood flow in skin flaps and other tissues, which can help prevent tissue death. 
• Blood clots: Leeches can remove blood clots and reduce congestion. 
• Inflammation: Leeches can help with inflammation and pain. 
• Cardiovascular disease: Leeches can help with circulatory disorders and cardiovascular disease. 
• Other conditions: Leeches can also help with abscesses, arthritis, glaucoma, myasthenia gravis, and venous disorders. 

During leech therapy, leeches are attached to the skin and secrete a mixture of proteins and peptides that thin the blood and prevent clotting. The leeches are sanitized and used only once. The treatment is painless because the leeches release a natural anesthetic when they bite.