Debridement is a procedure for treating a wound in the skin. It involves thoroughly cleaning the wound and removing all hyperkeratotic (thickened skin or callus), infected, and nonviable (necrotic or dead) tissue, foreign debris, and residual material from dressings. 

Wound debridement is the process of removing dead tissue from wounds. The dead tissue may be black, gray, yellow, tan, or white. Foreign material may also be on the wound. It may need to be removed. Your wound care doctor will let you know if dead tissue needs to be removed from your wound.