What is the fine-grained topic of the following text: There is a great deal of preliminary evidence that supports the traditional use of comfrey root as a topical application to speed healing, stop bleeding, prevent infection and relieve pain.Comfrey root is used to relieve pain from blunt injuries, promote healing of broken bones, sprains and bruises, reduce swelling and edema, and encourage the rapid and healthy regrowth of skin and tissue cells.PrecautionsNot for internal use. Only return the topic.
Traditional and medicinal uses of comfrey root