Dyspnea
Difficult or labored breathing; shortness of breath.</P> Dyspnea is a sign of serious disease of the airway, lungs, or heart.
The onset of dyspnea should not be ignored but is reason to seek medical attention.</P> The word dyspnea comes the Greek 'dys-', difficulty + 'pnoia', breathing = difficulty breathing.
Dyspnea is the American spelling and dyspnoea is the British (mis)spelling.