Abstract: An entirely self-contained, patient-worn apparatus for deep vein thrombosis (DVT) prophylaxis, and other conditions includes an inflatable/deflatable bladder disposed against an extremity such as the upper calf, foot, or hand of a patient, or within a cast. An inelastic member is preferably used to fully enclose the bladder and body part, such that compressive forces are directed substantially entirely against the body part of the patient when the bladder expands, thereby conserving the power and reducing the volume of pneumatic compression required to operate the device. Given this conservation of energy, the invention may be battery operated from a source immediately proximate to the bladder arrangement, enabling the entire device to be self-contained and, in fact, worn by the patient. The reduced volume also allows the use of miniaturized components including the compressor motor and compressor.