The correct diagnosis is important because the therapeutic approach for cardiac asthma is different from routine asthma treatment. Diuretics are often used to reduce the fluid that has built up in the lungs. If this treatment is successful, the wheezing problem is solved. Emphysema may also be a cause of symptoms that are suggestive of asthma. In fact, asthma and emphysema occur together.
Smoking is the primary cause of emphysema.
Unlike asthma, which is a reversible obstructive airway disease, the damage to the air sacs caused by emphysema is irreversible. The walls between the air sacs are permanently broken down in emphysema and as a result, there is less surface for the exchange of oxygen and carbon dioxide to occur. Less oxygen passes into the circulation, causing a build-up in the bloodstream of the body's waste product, carbon dioxide. Patients with emphysema are often short of breath and unable to exert themselves. Laboratory studies such as a chest x-ray, breathing tests including spirometry and a diffusion capacity of the lung for carbon monoxide study, and a study to determine the amount of oxygen in the arterial blood artery exercise.