Medicinal leeches are a type of segmented worm used in traditional and modern medicine. They are primarily known for their ability to suck blood, which can help improve circulation and reduce swelling in certain medical conditions. The saliva of leeches contains various bioactive substances that can promote healing and prevent blood clotting. These leeches are often used in reconstructive surgery and plastic surgery to assist in the recovery of tissues after surgery. They can help restore blood flow to areas that may be at risk of tissue death, making them a valuable tool in specific medical treatments.