Pulmonary hemorrhage (or pulmonary haemorrhage) is an acute bleeding from the lung, from the upper respiratory tract and the trachea, and the alveoli. When evident clinically, the condition is usually massive. The onset of pulmonary hemorrhage is characterized by cough productive of blood (hemoptysis) and worsening of oxygenation leading to cyanosis. Treatment should be immediate and should include tracheal suction, oxygen, positive pressure ventilation, and correction of underlying abnormalities (e.g. disorders of coagulation). A blood transfusion may be necessary.