Orthopnea or orthopnoea (Greek from ortho, straight + pnoia, breath) is shortness of breath (dyspnea) which occurs when lying flat, causing the person to have to sleep propped up in bed or sitting in a chair. It is the opposite of platypnea. It is commonly seen as a late manifestation of heart failure, resulting from fluid redistribution into the central circulation, causing an increase in pulmonary capillary pressure. It is also seen in cases of abdominal obesity or pulmonary disease.