Sometimes shortness of breath can be relieved by taking a few deep breaths or by resting. Dyspnea is a relatively common occurrence. It does not always indicate illness. Strenuous activity or anxiety may produce shortness of breath. Dyspnea may be caused by obesity or may develop as part of an allergic reaction.
Dyspnea occurs as a symptom of a variety of illnesses.
Usually the shortness of breath worsens on exertion, and is partially or completely relieved by rest. If you have left ventricular heart failure, you may avoid dyspnea in bed by sleeping with two or more pillows. If you have heart failure, you may experience dyspnea when you are sleeping. Shortness of breath usually occurs two to four hours after falling asleep. You will awaken with dyspnea, sweating, coughing and perhaps wheezing.