To diagnose chronic obstructive pulmonary disease (COPD), doctors typically use spirometry to measure your lung function. They usually also perform other tests to monitor the damage to your lungs.

Getting an official diagnosis of chronic obstructive pulmonary disease (COPD) can allow you to access medications that may improve your quality of life and help slow the condition’s progression. Doctors use a variety of tests to diagnose and monitor your lung function and the effects of COPD over time.

Your initial diagnosis may include:

  • a review of your medical and family history
  • a discussion about your symptoms and when they began
  • a look into your history of exposure to lung irritants, including cigarette smoke, air pollution, and chemicals
  • a physical examination, where a healthcare professional listens to your heart and lungs
  • spirometry, a test that measures your lung function

A doctor may order additional tests to better understand the damage to your lungs and their current function.

Keep reading to learn about the different tests doctors use to diagnose and monitor COPD.

Spirometry, a type of pulmonary function test (PFT) that measures lung function and capacity, is the typical method for diagnosing COPD.

To perform this test, you exhale as forcefully as possible into a tube connected to a spirometer, a small machine that measures:

  • the total volume of air exhaled from your lungs, or the forced vital capacity (FVC)
  • the percentage of the FVC in the first second, known as the FEV1, or forced expiratory volume
  • the maximum speed at which you empty your lungs, or the peak expiratory flow rate (PEFR)

A healthcare professional may have you perform the spirometry test again after you use an inhaled medication called a bronchodilator, which helps open the airways. This test may be called a bronchodilator reversibility test.

They can then compare your lung function with and without the medication and may interpret the results immediately.

Spirometry results help determine:

  • whether you have COPD
  • the type of COPD you may have
  • the severity of the condition

This test can tell doctors that you may have COPD before significant symptoms appear.

This screening is also helpful in monitoring people who have already received a diagnosis of COPD, asthma, or both. Test results can help a doctor determine whether your current bronchodilator therapy is working or if it needs to be adjusted.

Spirometry precautions

Because spirometry requires you to exhale forcefully, it’s not recommended for someone who has recently had a heart attack or heart surgery.

It’s important to be fully recovered from any serious illnesses or conditions prior to testing. Even if you’re in generally good health, you may feel a little breathless and dizzy immediately after the test.

Blood tests can help a doctor rule out other causes for your symptoms and better understand the severity of COPD.

Doctors can order specific blood tests to determine whether a respiratory infection may be causing any breathing symptoms, such as:

An arterial blood gas test, another type of blood test, measures the levels of oxygen and carbon dioxide in your blood. This is one sign of how well your lungs are working. This measurement can tell a doctor how severe your COPD is and whether you may need oxygen therapy.

Smoking and exposure to harmful substances in the environment are the most common causes of COPD, but there’s also a hereditary risk factor for this condition. A family history of premature COPD may mean that you have the condition.

Your doctor may check your levels of alpha-1 antitrypsin (AAT). This protein usually helps protect your lungs from inflammation caused by irritants like pollution or cigarette smoke. It’s produced by your liver and then released into your bloodstream.

People with low levels of AAT have a condition called alpha-1 antitrypsin deficiency and often develop COPD at a young age. Through genetic testing, you can find out whether you have an AAT deficiency.

Genetic testing for AAT deficiency is done with a blood test. The blood test is usually harmless.

Finding out you have an AAT deficiency may be challenging, especially if you haven’t received a diagnosis of COPD. Having an AAT deficiency doesn’t guarantee that you’ll eventually have lung problems, but it can increase the odds.

If you receive a COPD diagnosis but you’ve never smoked or worked around harmful chemicals and pollutants, or if you’re under 50 years old, you may have an AAT deficiency.

A CT scan is a type of X-ray that creates a more detailed image than a standard X-ray. Any type of X-ray that your doctor chooses will give a picture of the structures inside your chest, including your:

  • heart
  • lungs
  • blood vessels

Your doctor will be able to see if you have evidence of COPD. If your symptoms are being caused by another condition, such as heart failure, your doctor will be able to identify that as well.

CT scans and radiation

CT scans and standard X-rays are painless, but they do expose you to small amounts of radiation. Let your doctor know if you are pregnant.

The radiation used for a CT scan is greater than that required for a typical X-ray. While the doses of radiation for each test are relatively low, they do contribute to the amount of radiation exposure you receive over your lifetime.

However, new CT equipment requires less radiation to produce detailed images than previous technology.

Your doctor may order a sputum examination, especially if you have a productive cough. Sputum is the mucus you cough up.

Analyzing your sputum can help identify the cause of your breathing difficulties and may help detect:

Coughing enough to produce a sputum sample may be uncomfortable for a few moments. Otherwise, there are no real risks or downsides to a sputum examination. It can be very helpful in diagnosing your condition.

Your doctor might request an electrocardiogram (EKG) to determine whether your shortness of breath is being caused by a heart condition as opposed to a lung problem.

Over time, the breathing difficulties associated with COPD can lead to cardiac complications, including abnormal heart rhythms, heart failure, and heart attack.

An EKG measures the electrical activity in your heart and can help diagnose a disturbance in your heart rhythm.

The EKG is generally a safe test with few risks. Sometimes, you may experience a little skin irritation in the area where the electrode sticker is placed. Isopropyl alcohol or baby oil can help remove residue left behind by the electrode sticker.

If an EKG involves an exercise stress test, the screening may help uncover any abnormal heart rhythms.

COPD tests require little preparation. A member of the staff may recommend that you:

  • wear comfortable clothes
  • avoid big meals before your appointment
  • arrive at your appointment early to fill out any necessary paperwork

Prior to spirometry or EKG tests, let your doctor know about any medications you take or if you are pregnant. Certain drugs, caffeine, smoking, and exercise may affect your test results.

For example, if you’re having a bronchodilator reversibility test, you may need to hold off on using your bronchodilator until that portion of the test.

Check with your doctor or the testing center a few days before your test to see which restrictions apply to you. Make sure to follow all pre-testing instructions so that your results are as accurate as possible.

Usually, a doctor orders COPD tests, which are then performed at other healthcare facilities.

Blood tests may performed at a testing center and samples sent to a lab for study. You usually get your results within a couple of days or, at most, a couple of weeks.

Results of spirometry tests may take a couple of days to reach your doctor, though the doctor may be able to see them the same day if there’s urgency. The same is true of CT scans and other imaging tests.

Genetic testing tends to take a couple of weeks.

The results of a sputum culture can take anywhere from 1 or 2 days to a couple of weeks. The length of time depends on the type of condition being investigated.

Waiting for results can be difficult, but getting accurate test results is critical to properly diagnosing your condition and establishing an effective treatment plan.