paroxysmal nocturnal dyspnea (PND), a disorder characterized by sudden attacks of respiratory distress that awaken the person, usually after several hours of sleep in a reclining position. This occurs because of increased fluid central circulation with reclining position. It is most commonly caused by pulmonary edema resulting from congestive heart failure. The attacks are often accompanied by coughing, a feeling of suffocation, cold sweat, and tachycardia with a gallop rhythm. Sleeping with the head propped up on pillows may prevent PND, but treatment of the underlying cause is required to prevent fluid from accumulating in the lungs. Also called nocturnal paroxysmal dyspnea. See also dyspnea.
