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Lung Testing

Lung Testing

What types of tests are done on lungs to diagnose a problem?

UnityPoint Health - Pekin, wants to help you breathe easy. Whether you’re suffering COPD symptoms, need help with airway management or have other breathing trouble, here you’ll have access to some of the most advanced treatment and technology available in pulmonology and respiratory care. If you have additional questions, please call the Diagnostic Center at (309) 353-0410 or contact your physician.

What is a Pulmonary Function Test (PFT)?

Pulmonary Function Tests (PFTs) are a number of breathing tests that measure how well the lungs take in and exhale air and how efficiently they transfer oxygen into the blood. The following are terms that you might find helpful:


This test is performed by having you breathe into a mouthpiece that is connected to an instrument called a spirometer. The spirometer records the amount of air and the rate of air that is breathed in and out over a specified amount of time. Some tests require quiet, normal breathing; others are performed by forced exhalation or inhalation after a deep breath.

Lung Volume Measurements

This test is performed with you sitting in a sealed booth called a body plethysmograph. Changes in pressure inside the booth allow determination of the lung volume. This is the most accurate test to measure lung volumes. Lung volumes may also be measured when you breathe nitrogen or helium gas through a tube for a specified period of time. The concentration of gas in the chamber attached to the tube is measured, allowing estimation of lung volume.


The diffusion capacity is measured when a person breathes carbon monoxide for a very short time. The concentration of carbon monoxide in exhaled air is then measured. The difference in the amount of carbon monoxide inhaled and the amount exhaled allows estimation of how rapidly gas can travel from the lungs into the blood.

During a PFT, temporary shortness of breath or lightheadedness may be experienced. Testing time can be 1-2 hours, depending on what tests are to be performed. PFTs are performed to diagnose certain types of lung disease such as obstructive (asthma, bronchitis, emphysema), restrictive (inflammation or scarring of lung tissue), or abnormalities of the muscles or skeleton of the chest wall. PFTs are also performed to determine the cause of shortness of breath, to measure whether occupational exposure to contaminates affects lung function, to assess the effect of administered medications or to measure progress in disease treatment.

This test must be ordered by a physician. You will have to breathe into a tight fitting mouthpiece and wear nose clips during testing. If you are taking a regular PFT, you should have no caffeine or breathing medicines 60 minutes before test, and no cigarettes or alcohol. If you are taking a methacholine challenge, you should have nothing past midnight.

What is Respiratory Care?

Respiratory care is care given by a licensed Respiratory Therapist (RCP). Patients receiving respiratory care are usually inpatients. The upper respiratory tract is one of two parts of the respiratory system. It includes the mouth, nose, pharynx, larynx, and trachea. The upper tract delivers air to and from the lungs. The lower tract is made up of the bronchus, bronchioles and lungs.

If you have a lung disorder, asthma, bronchitis, or pneumonia, you may require respiratory treatments that can deliver medication to the lungs to relieve shortness of breath and hydrate dried secretions, allowing you to clear these secretions from the airway. Therapy may consist of supplemental oxygen, nebulizer treatment, chest percussion and suctioning the airway if necessary, pulse oximetry and drawing ABGs.

Respiratory care therapists respond to all "code blues" (patient has had respiratory or cardiac arrest) called throughout the hospital to work with the code blue team to provide life support to the patient.

What is Ventilator Therapy?

A ventilator is a machine used to aid or maintain breathing when a patient's breathing muscles have been compromised by disease, trauma or general anesthesia. Respiratory Therapists work closely with the physician by managing and maintaining the ventilator and are the only staff allowed to change settings on the ventilator.