Dyspnea (Shortness of Breath) Make an Appointment Find a Doctor Ask a Question Reviewed by Andrew M. Freeman, MD, FACC, FACP (December 01, 2012) Dyspnea, or being short of breath, experiencing “air hunger,” or having difficulty catching your breath, is a subjective symptom. There are no tools that can measure your sense of breathlessness. You may feel short of breath even though the pulse oximeter may read 93%. The important thing is to treat this symptom until you are comfortable and feel as if you are no longer short of breath. Dyspnea may be caused by tumor blocking an airway or replacing part of your lung, fluid in or around the lungs (edema, pleural effusion), blocked blood flow in the major blood vessels to the heart (superior vena cava syndrome), blood clots in your lungs (pulmonary emboli), pneumonia or other respiratory infection, anemia (low red blood cell count), or hyperventilation due to anxiety. Sudden dyspnea or a rapid feeling of air hunger may indicate a medical emergency. Call 911 if you experience severe symptoms. Otherwise, call the Lung Cancer Center staff to discuss your symptoms. Prolonged dyspnea can lead to confusion and weakness, increasing your risk of falls. Symptoms of Dyspnea: Difficult or labored breathing Feeling of suffocation or smothering Inability to get enough air Tightness or pains in the chest Programs & Services Cardiology Programs Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.