Platypnea: Symptoms & Signs

Medically Reviewed on 4/26/2022

Platypnea refers to the rare condition of shortness of breath or difficulty breathing that occurs when standing up or sitting that is relieved by lying flat. Platypnea is less common than orthopnea, which refers to shortness of breath when lying down that is relieved by assuming an upright position. Other associated signs and symptoms depend on the cause of platypnea and can include

  • general shortness of breath,
  • cough, and
  • low oxygen saturation (orthodeoxia) when standing.

The cause of platypnea is not well understood. It is thought to arise from conditions that cause shifts in the normal pattern of blood flow between the arterial and the venous circulation, such as septal defects in the heart or hepatopulmonary syndrome. Sometimes, people with severe diseases of the lung develop platypnea due to a mismatch between ventilated areas of the lung and areas that are reached by the circulation (ventilation-perfusion mismatch).

Other causes of platypnea

  • Atrial Septal Defect
  • Hepatopulmonary Syndrome
  • Intracardiac Shunt
  • Patent Foramen Ovale
  • Pericardial Effusion
  • Post-Pneumonectomy


COPD (chronic obstructive pulmonary disease) is the same as adult-onset asthma. See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.