Dyspnea, also known as shortness of breath, is a medical term for difficult or labored respiration. It is a symptom of many different conditions and can range from mild to severe. Dyspnea is often caused by an underlying medical condition such as asthma, COPD, or heart failure. It can also be caused by physical exertion or anxiety. Treatment for dyspnea depends on the underlying cause and may include medications, lifestyle changes, or oxygen therapy.