The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

Pulmonary Function Tests (PFT)

Objective measurement of respiratory mechanics and gas exchange

Written by: Saygı Hospital Health Guide Editorial Board
Published:

This content is for general information; please consult your physician for diagnosis and treatment.

References (5)

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Göğüs Hastalıkları department. Book Appointment →

What is Pulmonary Function Tests (PFT)?

Pulmonary function tests (PFTs) encompass a variety of physiologic tests evaluating different aspects of respiratory function. The core components include spirometry, lung volumes (via plethysmography, helium dilution, or nitrogen washout), diffusing capacity for carbon monoxide (DLCO), bronchodilator response, and bronchoprovocation testing.

Spirometry measures forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and derived indices (FEV1/FVC ratio, FEF25-75%). Patterns include obstructive (reduced FEV1/FVC ratio, seen in COPD and asthma), restrictive (reduced FVC and TLC, seen in interstitial lung disease and chest wall disorders), and mixed patterns.

Lung volumes provide information not obtainable from spirometry, including total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC). Essential for diagnosing restrictive physiology, hyperinflation, and air trapping.

DLCO assesses alveolar-capillary membrane function; reduced in emphysema, ILD, pulmonary vascular disease. Bronchodilator reversibility (FEV1 increase ≥12% and ≥200 mL) supports asthma diagnosis. Methacholine challenge identifies airway hyperresponsiveness.

Symptoms

PFT indications include unexplained dyspnea, cough, wheezing, abnormal chest imaging
Preoperative risk assessment for thoracic, abdominal, or major surgery
Occupational exposure evaluation and disability assessment
Monitoring known respiratory diseases (COPD, asthma, ILD, CF, neuromuscular disease)
Drug toxicity screening (bleomycin, amiodarone, nitrofurantoin, methotrexate)
Post-lung transplant monitoring and response to therapy

Risk Factors

Obstructive patterns: smoking, asthma, COPD, bronchiectasis, cystic fibrosis
Restrictive patterns: ILD/IPF, pulmonary fibrosis, chest wall deformity, obesity, neuromuscular disease
Mixed obstructive-restrictive: advanced combined emphysema and pulmonary fibrosis
DLCO reduction: emphysema, ILD, pulmonary embolism, pulmonary hypertension, anemia
DLCO elevation: asthma, obesity, polycythemia, left-to-right shunts, alveolar hemorrhage
Bronchodilator responsiveness: asthma, sometimes COPD and other airway diseases

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • Persistent respiratory symptoms — dyspnea, chronic cough, wheezing — warrant PFT as part of diagnostic evaluation.
  • Abnormal chest imaging (nodules, consolidation, interstitial changes) or occupational exposure history should prompt PFT assessment.
  • Monitoring of known respiratory disease progression, pre-surgical risk evaluation, and response to therapy require periodic PFT assessment by pulmonary specialist.

Treatment Methods

01
Standardized spirometry with appropriate quality controls (acceptability and repeatability criteria per ATS/ERS guidelines).
02
Comprehensive interpretation using GLI (Global Lung Initiative) reference equations, with lower limit of normal (LLN) or z-scores rather than fixed ratios.
03
Bronchodilator response assessment for patients with airflow obstruction to identify reversibility and support asthma/COPD distinction.
04
Full PFT with lung volumes and DLCO for suspected restrictive disease, emphysema quantification, or pulmonary vascular disease evaluation.
05
Specialized testing: bronchoprovocation (methacholine, mannitol, exercise) for suspected asthma with normal baseline spirometry; cardiopulmonary exercise testing for unexplained dyspnea.
06
Serial monitoring: annually for COPD/ILD/CF, more frequently for progressive disease or treatment response assessment; pre/post-therapy to document drug efficacy.

Which Department to Visit?

You can visit our Göğüs Hastalıkları department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Göğüs Hastalıkları Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Asthma

Göğüs Hastalıkları

Asthma is characterized by wheezing, coughing and shortness of breath attacks; with proper treatment it can be kept under control.

COPD (Chronic Obstructive Pulmonary Disease)

Göğüs Hastalıkları

COPD is an irreversible lung disease characterized by shortness of breath and chronic cough; quitting smoking slows its progression.

Pneumonia

Göğüs Hastalıkları

Pneumonia presents with high fever, cough and shortness of breath; the vast majority recover with appropriate antibiotic treatment.

Tuberculosis (TB)

Göğüs Hastalıkları

Tuberculosis presents with weeks-to-months of cough, fever, and night sweats; early diagnosis and treatment lead to full recovery.

Pleural Effusion

Göğüs Hastalıkları

Pleural effusion is the accumulation of excess fluid in the pleural space, resulting from imbalances in fluid production and removal, and represents a manifestation of diverse cardiopulmonary, infectious, and malignant disorders.

Pneumothorax

Göğüs Hastalıkları

Pneumothorax is the presence of air in the pleural space resulting in partial or complete lung collapse, classified as spontaneous (primary/secondary), traumatic, or iatrogenic, with tension pneumothorax representing a life-threatening emergency.

Bronchitis (Acute and Chronic)

Göğüs Hastalıkları

Acute bronchitis is mostly viral and resolves spontaneously, while chronic bronchitis is a smoking-related component of COPD.

Bronchiectasis

Göğüs Hastalıkları

Bronchiectasis is a chronic respiratory disease characterized by permanent, abnormal dilation of bronchi with associated destruction of muscular and elastic components of airway walls, resulting in impaired mucociliary clearance and recurrent infection.

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.