19 Respiratory Distress

Paroxysmal nocturnal dyspnea (or PND) refers to attacks of severe shortness of breath and coughing that generally occur at night.[1] It usually awakens the person from sleep, and may be quite frightening.[2] Though simple orthopnea may be relieved by sitting upright at the side of the bed with legs dependent (legs dangling),[3] in a patient with paroxysmal nocturnal dyspnea, coughing and wheezing often persist even in this position.

Source: http://en.wikipedia.org/wiki/Paroxysmal_nocturnal_dyspnea