To surive injury, whole-body recovery and tissue repair are mutually essential. Recovery is aided by increased mobility, return of appetite, and probaly sleep. The repair of soft connective tissues begins with collogen-platelet interactions followed by a cellular-humoral phase and later the formation of scar tissue. In hard connective tissue, exemplified by the skeleton, the repair of fracture most commonly goes through phases similar to those at the growth plate of bone, with the initial formation of a mineralized cartilage matrix, later replaced by woven and lamellar bone which is subsequently remodelled. Many obvious factors such as malnutrition, vitamin deficiency and infection delay healing. Current investigations deal with the way in which cells communicate during tissue repair, the role of local hormones, and the relation between physical and electrical forces and cell function.