Poor blood flow and wound oxygenation will not support granulation tissue production, affecting scarring and more severe loss of oxygenation to the wound, which can lead to increased risk of infection. Related issues include anemia or any similar manifestation. Malnutrition, infection or tissue damage significantly increases calorie and protein needs. The needs for Vitamins C, A, B, as well as the need for Iron, Copper, and Zinc are also increased. Concurrent disease, i.e., diabetes mellitus, immunosuppression, age, other systemic conditions such as liver failure, kidney failure, malignancies, edema, or inadequate hydration will also adversely affect wound healing.
Extrinsic factors are factors that originate outside the patient.
It is important that these causative factors be addressed and eliminated, or it is likely that the wound will not heal. Extrinsic factors can include pressure, shear, and friction, excessive moisture, or repeated and continued trauma to the wound site. With all of the above considerations, it is easy to see that wound healing is a complex and overlapping process. The concept of the wound healing continuum recognized the dynamic nature of wound healing and indicates the type of tissue and drainage likely to be found in each phase. It can serve as a guide to understanding wound healing as well as a management tool for choosing local wound care.