A Pulmonary Function Test (PFT) is a non-invasive diagnostic procedure that measures how effectively your lungs are working. This testing evaluates how much air your lungs can hold, how quickly you can move air in and out, and how well your lungs transfer oxygen into the blood. PFTs are frequently used to help diagnose conditions such as asthma, Chronic Obstructive Pulmonary Disease (COPD), and pulmonary fibrosis, or to monitor known lung conditions. The test provides measurable data on lung mechanics and gas exchange, helping healthcare providers determine the severity of pulmonary impairment. This information is also used to assess a patient’s response to treatment or evaluate lung health before major surgery.
Identifying Appropriate Testing Facilities
Pulmonary Function Tests are performed in several types of medical environments, depending on the complexity of the specific test required. Hospital pulmonary laboratories are equipped to handle the full range of PFTs, including sophisticated procedures like body plethysmography for lung volume measurement and diffusion capacity testing (DLCO). These labs typically serve patients requiring comprehensive or specialized evaluations.
Specialized outpatient respiratory clinics are another common location, often offering a full suite of testing services outside of a hospital setting. These dedicated centers are staffed by respiratory therapists and technologists who specialize in conducting these detailed breathing maneuvers. For the most common PFT, known as spirometry, testing can also be performed in a pulmonologist’s or allergist’s office, as this procedure requires less complex equipment.
The Referral and Scheduling Process
Accessing a Pulmonary Function Test almost always begins with obtaining a physician’s order or referral. Your primary care doctor or specialist must formally request the test, specifying the exact procedures needed, such as simple spirometry or a complete PFT with bronchodilator response. This referral is a medical prerequisite, providing the necessary diagnostic codes and medical justification for the testing facility.
Once the order is in place, coordination begins with your insurance provider and the testing facility. It is important to confirm coverage for the specific PFT procedure requested, as some insurance plans may require pre-authorization before scheduling. Contacting the facility’s billing department beforehand allows you to discuss any anticipated out-of-pocket costs.
The facility’s scheduling office will contact you to book the appointment after the referral and insurance details are confirmed. The time allotted for the test can vary significantly; basic spirometry might take about 30 minutes, while a complete PFT can take 60 minutes or longer. Providing accurate contact and insurance information helps prevent delays and ensures the facility has the necessary paperwork prepared.
Preparing for the Test and What Happens During
Preparation
Proper preparation is necessary to ensure the accuracy of the PFT results. Patients are typically instructed to avoid using specific inhaled bronchodilator medications for a defined period before the test, often four to twelve hours. If you are taking an inhaled corticosteroid or a long-acting bronchodilator, your physician may provide specific instructions to withhold the medication for a longer duration.
Other preparatory steps include avoiding heavy meals for a few hours before the appointment, as a full stomach can restrict the diaphragm and impact breathing efforts. You should also refrain from smoking for at least one hour and avoid vigorous exercise or caffeine consumption on the day of the test. Wearing loose-fitting clothing is recommended to ensure there is no restriction around your chest or abdomen during the required deep breaths.
The Procedure
During the procedure, you will sit and be asked to breathe through a sterile mouthpiece connected to a spirometer, with a soft clip placed on your nose. A respiratory therapist will guide you through a series of breathing maneuvers. These typically involve taking a maximal breath in and then exhaling forcefully and completely for several seconds. You may be asked to repeat these efforts multiple times to ensure a consistent and reliable reading is obtained.