A method of analyzing a patient's tissue oxygenation capabilities includes measuring a tissue chromophore whose light absorption properties depend on the oxygenation state of the tissue and generating data representative of tissue oxygenation before, during and after a controlled ischemia event. From this data characterizing data, including ischemia onset slope, ischemia onset response time, ischemia recovery slope, ischemia recovery response time or hyperemia is automatically determined. This characterizing data is related to corresponding characterizing data determined from a control population. The relationship may be displayed on a graphical display.