Quick & Easy Tips for Relief from Shortness of Breath Fast: Shortness of breath means you are having complexity breathing or feeling suffocated. Shortness of breath is a very common problem that most of us suffer about from time to time. Sudden breathing problem can be mild, moderate or severe. In some cases, It is normal to experience some shortness of breath when you exceed your normal activity level or climb to high altitudes where there is less oxygen in the air. However, it is due to a some of the health issues. It can be caused by anemia, heart disease, respiratory infection or disease, bronchitis, and allergies. It is a very common symptom in the person suffering from lung cancer.