Shortness of breath

[Ernesto]

Shortness of breath—what doctors call dyspnea—is the unpleasant sensation of having difficulty breathing. People experience and describe shortness of breath differently depending on the cause.
The rate and depth of breathing normally increase during exercise and at high altitudes, but the increase seldom causes discomfort. Breathing rate is also increased at rest in people with many disorders, whether of the lungs or other parts of the body. For example, people with a fever generally breathe faster.
With dyspnea, faster breathing is accompanied by the sensation of running out of air. People feel as if they cannot breathe fast enough or deeply enough. They may notice that more effort is needed to expand the chest when breathing in or to expel air when breathing out. They may also have the uncomfortable sensation that inhaling (inspiration) is urgently needed before exhaling (expiration) is completed and have various sensations often described as tightness in the chest.
Other symptoms, such as cough or chest pain, may be present depending on the cause of dyspnea.