What Are the Tests Used for an Emphysema Diagnosis?

Steps in Diagnosing Emphysema from Symptoms to Scans

If your doctor has told you that you should be tested for emphysema, you may be wondering what tests are used to make the diagnosis.

Emphysema is a form of the chronic obstructive pulmonary disease, or COPD, that involves damage to the alveoli, the tiny air sacs in which the exchange of oxygen and carbon dioxide takes place. When this damage occurs, it can make it more difficult to breathe.

You and your doctor may be concerned if you have any signs or symptoms of emphysema such as shortness of breath, a chronic cough (with or without sputum production,) reduced exercise tolerance or unintended weight loss.

Diagnosing emphysema often involves evaluating your lung function as well as making sure you don't have other causes of your symptoms. Let's take a closer look at some of the tests used to make this diagnosis.

History and Physical

doctor listening to a patients lungs
A diagnosis of emphysema begins with a careful history and physical. Justin Sullivan / Getty Images

The presenting symptoms and findings made during a physical examination provide your doctor with the initial clues to any health problem, emphysema included.

During your office visit, your doctor will ask you a number of questions related to your history. This will include asking about the most common symptoms such as:

  • A persistent cough (with or without coughing up sputum)
  • Rapid breathing (tachypnea) - A normal respiratory rate in adults is 12 to 18 breaths per minute
  • Shortness of breath
  • Less ability to exercise than in the past
  • Weight loss
  • Reduced appetite
  • Wheezing
  • Poor sleep
  • Depression

She will also ask you about risk factors for emphysema such as smoking, secondhand smoke, and home and occupational exposures to chemicals and other substances.

It's important to note that while emphysema is often caused by smoking, people who have never smoked may develop the disease as well.

You will also be asked you about your family history. Some causes of emphysema, such as alpha-1-antitrypsin deficiency, run in families. It's especially important to let your doctor know if any members of your family had emphysema but did not smoke.

After taking a careful history, your doctor will perform a physical exam. She will listen to your lungs, but also look for other signs of emphysema such as:

  • Abnormal breath sounds
  • A barrel chest (A barrel chest refers to a rounding of the chest which may occur due to hyperinflation of the lungs)
  • Muscle wasting
  • Weight loss
  • Clubbing of your nails (Clubbing is a symptom in which the ends of the fingers take on the appearance of upside-down spoons)
  • The use of accessory muscles - When people are trying hard to breathe with lung diseases it's common to see a contraction of the neck muscles in an attempt to get more air.

Chest X-Ray

Emphysema Lung Radio
Different pulmonary function tests can help pin down a diagnosis of emphysema. BSIP / Getty Images

A chest x-ray is a radiographic examination of the lungs, heart, large arteries, ribs, and diaphragm. A chest x-ray can be performed in a radiology lab, doctor's office or at your bedside if you are in the hospital.

Your doctor will perform an initial chest x-ray to help her reach a diagnosis of emphysema, and then intermittently throughout your treatment to monitor your progress. On an x-ray, emphysematous lungs look hyper Lucent with normal markings from blood vessels being less prominent. The diaphragms also appear flattened due to the hyperinflation of the lungs (which pushes down on the diaphragm.) Unfortunately, changes on x-ray are not usually seen until the disease is quite extensive.

Often, a chest CT scan will be performed, both to help with the diagnosis and to rule out other conditions which may cause similar symptoms such as lung cancer.

Pulmonary Function Tests

Doctors palpate an emphysema patient. Tino Soriano / Getty Images

Pulmonary function tests (PFTs) are performed to assess lung function and determine the degree of damage to the lungs.

In patients with emphysema, there may be an increase in total lung capacity (TLC,) the total amount of air you can breathe in after taking the deepest breath possible but a decrease in vital capacity (the amount of air which can be inhaled or exhaled from the lungs) and forced expiratory volume (FEV,) the maximum amount of air which can be exhaled (often the maximum amount which can be exhaled in one second.) Diffusing capacity is another important measurement. It tests how well oxygen diffuses from the alveoli into the bloodstream (capillaries) and how well carbon dioxide diffuses from the bloodstream into the alveoli to be exhaled.

Spirometry is a simple test that is often done to monitor emphysema. It measures the amount and how fast you can breathe in and breathe out.

Another test called Lung plethysmography may also be done in order to determine your functional residual capacity, the amount of air left in your lungs after taking a normal breath. It is often used when the diagnosis is uncertain in order to distinguish obstructive vs restrictive lung diseases.

All of these terms are confusing, but to understand your disease it's important for your doctor to explain what they are and what they mean. Understanding where these numbers are at the time of diagnosis can help you understand if your symptoms are improving or worsening after treatment.

Arterial Blood Gases

human heart
ABG's measure oxygen and carbon dioxide as well as the pH of the body. luismmolina / Getty Images

Arterial blood gases (ABGs) are performed by taking blood from an artery, such as the radial artery in your wrist or your femoral artery in your groin.

This test measures the amount of oxygen and carbon dioxide in the blood and also lets you and your doctor know about the acidity (the pH) of your blood.

ABGs may be used to help diagnose the severity of your disease as well as response to treatments.

Complete Blood Count

Red Blood Cells in Bloodstream
A CBC may find infections in people with emphysema. Science Picture Co / Getty Images

The complete blood count (CBC) is a blood test which can be used to help diagnose emphysema as well as manage a variety of conditions.

A CBC is usually done during your initial physical examination and then periodically to monitor your condition.

Your doctor will likely check your CBC often, as this is one way to detect the presence of an infection. Since lung infections and emphysema may have very similar symptoms, this test can help your doctor determine if any symptoms you have are related to your COPD or if, instead, you may have an infection exacerbating your COPD.

An Emphysema Diagnosis

Male patient and doctor in discussion in exam room
It is important to recognize a diagnosis of emphysema as early as possible. Thomas Barwick / Getty Images

The importance an early diagnosis of emphysema cannot be overemphasized. While emphysema is not reversible by definition, early emphysema treatment and careful monitoring can help to slow the progression of the disease and improve your quality of life.

Sources

  • Kasper, Dennis L.., Anthony S. Fauci, and Stephen L.. Hauser. Harrison's Principles of Internal Medicine. New York: Mc Graw-Hill Education, 2015. Print.
  • National Heart, Lung, and Blood Institute. COPD. Diagnosis. Updated 04/28/17. 

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