How is COPD diagnosed?
Healthcare providers go through several steps to find out if a person has chronic obstructive pulmonary disease (COPD):
- The patient starts to have symptoms that can be signs of COPD.
- The healthcare provider finds out more about the patient’s work, family, and medical history to find out about “risk factors.”
- The patient is asked to have special tests that can help diagnose COPD.
- If the patient has COPD, the tests can be used to find out the stage of the disease.
People with COPD usually have a cough that does not go away for weeks or months. Their lungs also produce an increased amount of mucus that can cause them to cough it up and/or clear their throats more often.
Other symptoms that can be signs of COPD are:
- Chest tightness
- Blueness of the lips and fingernail beds
- Weight loss
- Swelling in the ankles, legs and feet
What are risk factors for COPD?1,2
Risk factors for COPD are things in a person’s work, family, or medical history that can cause a higher risk of getting COPD. If people have one or more risk factors for COPD, then it is more likely that their symptoms are caused by COPD and not something else.
The strongest risk factor for COPD is being a current or former smoker. Another risk factor is working in a place where you breathe in irritants on a regular basis.
If COPD seems likely based on the person’s symptoms and risk factors, then special testing can find out for sure.
What kinds of tests are used to diagnose COPD and find out the stage?
Two breathing tests can be used to measure how well a person’s lungs are working:
“Spirometry” is the most important test used to diagnose COPD. Spirometry is a breathing test that measures:
- The amount of air that a person can breathe out at once
- How fast the lungs can be emptied
People with COPD have airways that are blocked by lung damage caused by the disease. The results of the spirometry test show whether or not the person’s airways are blocked. Spirometry is also used to find out what stage of COPD a person has.
The lung volume measurement test can also show how well a person’s lungs are functioning. It measures the amount of air in a person’s lungs when breathing in and breathing out.
People with COPD have lung damage that keeps their lungs from absorbing enough oxygen from the air they breathe. There are other types of tests that can measure the amount of oxygen in a person’s blood or breath. If the tests show that the person’s oxygen levels are too low, it can be a sign of COPD. Tests that are commonly used are:
- Pulse oximetry test
- Arterial blood gas test
- Lung diffusion capacity test
Another kind of testing called “imaging” can also be helpful in diagnosing a person with COPD or finding out the stage of disease. Imaging tests include:
- Chest x-ray
- CT scan
Imaging tests are not used alone to diagnose COPD, but they can provide extra useful information. They can also be used to make sure that a person’s symptoms are not being caused by some other condition with similar symptoms.