The present disclosure provides methods and apparatus for evaluating the flow of blood in damaged or healing tissue. The present disclosure also provides methods of identifying a patient at the onset of risk of pressure ulcer or at risk of the onset of pressure ulcer, and treating the patient with anatomy-specific clinical intervention selected based on perfusion or blood oxygenation values, or a combination thereof. The present disclosure also provides methods of stratifying groups of patients based on risk of wound development and methods of reducing incidence of tissue damage in a care facility. The present disclosure also provides methods to analyze trends of perfusion or oxygenation measurements to detect tissue damage before it is visible, and methods to compare bisymmetric perfusion values to identify damaged tissue.
