How Is Emphysema Diagnosed?Thursday, March 22, 2012 - 11:32
If your doctor suspects emphysema, he or she will use the following methods to diagnose and determine the severity of the disease:
- History and physical examination
- Chest x-ray and, possibly, a CT scan of your chest
- Lung function tests
- Testing for alpha-1 antitrypsin deficiency (AAT deficiency)
The doctor's examination will include a review of your symptoms and a discussion of your medical history, including whether you smoke or have smoked in the past. The doctor also will ask about the type of work to do, to determine if you might be breathing any harmful chemicals on the job.
A physical examination will include an examination of your chest and breathing patterns. The doctor will:
- Look for
nasal flaringand other signs that you are working very hard to breathe.
- Check for over-inflation of your lungs.
- Listen to your chest with a stethoscope to hear the airflow in and out of the lungs
- Listen to heart sounds to determine rate, rhythm and any signs of heart strain that are seen in the later stages of emphysema.
Chest x-rays deliver very little radiation to the body and are very safe. Chest x-rays are a very useful tool to evaluate anatomy of the lung. In emphysema, there is evidence of increased air in the chest and destruction of some of the lung tissue. Bronchitis can be suspected on a chest x-ray by presence of thickening of the tissue around the large airways (bronchi). Chest x-rays are also useful as screening for lung cancer and heart disease.
Computerized axial tomography or CAT scans indicate lung anatomy in greater detail. In some cases, this information is needed to fully evaluate lung disease. These studies, however, deliver more radiation and are considerably more expensive.
For more information about CT Scan, go to CT Scan.
Routine lung function tests can help define the kind and amount of damage to the lungs. The following tests can identify various stages of emphysema:
Spirometrymeasures breathing capacity. A common measure of breathing capacity is the forced expiratory volume in one second (FEV1), or the amount of air that can be forced out of the lungs in one second. This is a common way to determine the amount of airway obstruction.
- Frequently, your physician will ask that spirometry and body plethysmography (see below) be repeated after administration of an inhaled
bronchodilator(see below). This test will help your physician determine if there is an asthmatic component present; if so, your physician will probably suggest that you use bronchodilator medication (see below)
- Lung Volumes measures the amount of air in the lungs. This increases markedly in emphysema.
- Diffusing Capacity measures the ability of the lung to transfer the gases from the air to the blood and vice versa. Decrease in diffusing capacity allow fairly accurate estimation of amount of emphysema.
- Body Plethysmography is a rapid way of evaluating both degree and type of obstruction and lung volumes. It is an useful adjunct to understanding the mechanism of airway obstruction - e.g., asthma vs emphysema.
- Arterial blood gases (ABG) analyzes blood from an artery for amounts of carbon dioxide and oxygen. This test is often used in more advanced stages of emphysema to help determine if a person needs supplemental oxygen.
The symptoms of alpha-1 antitrypsin deficiency-related emphysema tend to appear between the ages of 30 and 40. The symptoms and diagnostic tests are basically the same in any kind of emphysema except that, in this disease, emphysematous changes are greatest in the lower lung. However, if AAT deficiency is suspected, a special blood test can confirm the diagnosis.
Need To Know:
Emphysema almost never occurs in people who don't smoke. When it does, it's usually because of AAT deficiency.
In people who have AAT deficiency, emphysema will occur much later in life if they do not smoke.