A device for identifying changes in or elevated levels of compartment pressure has a blood-volume sensor adapted to be arranged at a distal blood-flow region relative to a region of interest, and a data processor in communication with the blood-volume sensor. The data processor is configured to receive a data signal from the blood-volume sensor, obtain a reference signal, compare the data signal to the reference signal to identify a difference between the reference signal and the data signal that is indicative of an change in pressure within the region of interest, and identify at least one of changes in or elevated levels of compartment pressure in the region of interest based on the comparing.