How is COPD Diagnosed?

• Spirometry - You will be asked to breathe into a tube connected to a machine.  The machine measures the amount of air you move in and out of your lungs and how well the air moves.
   
• Pulmonary Function Tests – In addition to spirometry, other tests may be done to find out if your health problem is related to your lungs. These tests measure how much air you move in and out of your lungs and how successful your lungs are at exchanging the gases oxygen and carbon dioxide with your bloodstream.
   
• Arterial Blood Gases (ABGs) - Your doctor will order this test to determine the amount of oxygen in your blood and how well your lungs are getting rid of carbon dioxide. ABGs are usually ordered if you have very severe COPD and are hospitalized.
   
• Chest X-ray – Emphysema produces distinctive abnormalities in the chest X-ray, which may also be used to rule out other diagnoses such as pneumonia or lung tumors.
   
• Oximetry – This test is a way of indirectly measuring oxygen levels in your blood. It is done by placing a small strap around your finger.  Because oximetry machines can be unreliable, ABGs are generally the preferred test when determining if you need supplemental oxygen.
   
• Exercise Testing – It may be used to help determine the amount of disability and help determine if a patient can safely undergo lung resection surgery. An exercise test is done in a laboratory, either by having you walk on a treadmill or pedal a bicycle.
   
• Electrocardiogram (ECG) – ECG is used to assess your heart status if heart disease is suspected or present.  Severe COPD causes strain on the right side of the heart, which produces characteristic changes in the ECG.
   
• Sputum Culture – This test is ordered to diagnose the type of bacterial infection when a patient has recurring bronchitis or pneumonia.
  

Source:  Global Initiative for Chronic Obstructive Lung Disease