Pulmonary Function Tests (PFTs, Pulmonary Function Studies, Lung
Function Studies/Tests, Airflow Assessment) What are pulmonary
function tests? Pulmonary function tests (PFTs) are noninvasive
diagnostic tests that provide measurable feedback about the
function of the lungs. By assessing lung volumes, capacities,
rates of flow, and gas exchange, PFTs provide information that,
when evaluated by your doctor, can help diagnosis certain lung
disorders. A normally-functioning pulmonary system operates on
many different levels to ensure adequate balance. One of the
primary functions of the pulmonary system is ventilation, the
movement of air into and out of the lungs. Some medical
conditions may interfere with ventilation. These conditions may
lead to chronic lung disease. Conditions that interfere with
normal ventilation are categorized as restrictive or
obstructive. An obstructive condition occurs when air has
difficulty flowing out of the lungs due to resistance, causing a
decreased flow of air. A restrictive con