In examination of 817 patients with closed chest injury and multiple trauma 57% of them were found to have obvious or latent hemopleuritis. According to the character of the primary damage and the developing pathophysiological changes, 3 forms of hemopleuritis were revealed: cardiac, pulmonary, and abdominal. A single complex of symptoms forms finally: pulmonary hypertension, venous stasis in the lungs, right-ventricular cardiac insufficiency. As a result, venous blood escapes through the lymph nodes, mainly those of the right lung, and together with the lymph flows in the dilated lymph vessels of the lungs into the pleural cavity. The differential-diagnostic signs of each form of hemopleuritis are pointed out, the prognostic criteria of their development are revealed, and the pathogenetically substantiated therapy is determined.