The physiology of wound healing

Wound healing is a complex biological process which results in the restoration of tissue integrity. Physiologically, it can be broken down into four distinct phases of haemostasis, inflammation, proliferation and tissue remodelling. This article describes the cellular basis of wound healing and the extracellular signalling processes which control them. The function of platelets, neutrophils, macrophages and fibroblasts are considered in detail. The concept of healing by primary and secondary intention is discussed. Many factors are known to adversely affect healing including malnutrition, hypoxia, immunosuppression, chronic disease and surgery. It is essential that surgeons understand the key physiological processes involved in healing in order to minimize patient morbidity from delayed healing.