Shortness of breath
Few sensations are as frightening as not being able to get enough air. Shortness of breath — known medically as dyspnea — is often described as an intense tightening in the chest, air hunger or a feeling of suffocation.
Very strenuous exercise, extreme temperatures, massive obesity and high altitude all can cause shortness of breath in a healthy person. Outside of these examples, shortness of breath is likely a sign of a medical problem.
If you have unexplained shortness of breath, especially if it comes on suddenly and is severe, see your doctor as soon as possible.