A Guide to Pulmonary Function Test Results

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We take for granted the ability to breathe because it is something we do not have to think about. However, for some people breathing can involve a lot of work and it can be painful and difficult. By understanding the results of the most recent pulmonary function tests, a doctor is able to diagnose and prescribe the treatment that is needed.


One of the first pulmonary function tests is called the spirometry. This is a handy test to see the level of breathing within a person. It also measures the persons pulmonary capacity. With this test, the individual will need to place his mouth over a mouthpiece and breathe deeply into it. The physician will then monitor how long it takes the lungs to fill and expel air. During this test, the doctor will test what is happening during the process of gas exchange. Thus, he will check if oxygen and carbon dioxide is being exchanged in suitable volumes. A review of the results is made of the spirometer results that is shown as a printout. This can determine the condition of the lungs based on the graph generated by the spirometry test.

Other pulmonary function test results can show how fast gas is exchanged from the lungs into the blood. If there is a problem it will go on to affect all areas of the body. This other pulmonary function test is known as a gas diffusion test. It is mainly used to show how much carbon dioxide is exchanged by the alveoli. It is possible that a small amount of carbon dioxide will be administered and tests ordered to assess the diffusion capacity of the lungs.

Understanding Lung Function Tests

Once the spirometry graph has been generated, it will be necessary to review it. The spirometer graph is one of the pulmonary lung function test results that measures the FVC and FEV1. The FVC result should be around 85 percent and it is a measurement of the amount of forced air that is exhaled after a large inhalation. If the result is less than 85 percent of the predicted value, the physician will determine if a restrictive or obstructive lung disease is affecting the person.

The spirometry will also show the FEV1. This is known as the forced amount of air that occurs in one second. This is the amount that can be exhaled forcibly at one second after starting exhalation. It also should be around 85 percent. The individual will need to understand this concept to understand his results.

Another way in which a lung function test can be understood is to show the lung volume. This is especially true in situations such as restrictive diseases of the lungs that can cause less air to reach the lung alveoli and subsequently the body’s tissues.

Keep in mind that all of the results received will be read, understood and explained to the person by the physician. The doctor will explain the tests as it relates specifically to the body and what is the next step in the treatment phase.


Cleveland Clinic: Interpreting Pulmonary Function Tests

Medline: Pulmonary Function Tests