At one time, the use of leeches to treat medical problems was quite common. If a person suffered from a snake bite or a bee sting, leeches were believed to be capable of removing the poison from the body if they were placed on top of the wound. They have also been used for bloodletting and to stop hemorrhages, although neither of these leech treatments would be considered acceptable by present-day physicians. Today, leeches are still used on a limited basis. Most often, leeches are used to drain blood from clogged veins. This results in little pain for the patient and also ensures the patient’s blood will not clot while it is being drained.The main purpose of the passage is

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