PFT & DLCO
Comprehensive lung function testing to measure how well your lungs inhale, exhale, and transfer oxygen to the blood. Essential for diagnosing and managing respiratory conditions.
What is a pulmonary function test (PFT)?
Pulmonary Function Tests (PFTs) are a group of non-invasive breathing tests that measure how well your lungs work. They evaluate lung volume, capacity, flow rates, and gas exchange—providing essential information to diagnose and manage respiratory conditions.
At Aelira Lung Health Centre, we perform comprehensive PFT testing using advanced, calibrated equipment. Our experienced respiratory technicians ensure accurate, reproducible results with detailed clinical interpretation.
15-60 minutes
Test duration
Same-day reports
With interpretation
Types of pulmonary function tests
We offer a complete range of PFT tests tailored to your diagnostic needs. Your doctor will recommend the appropriate test based on your symptoms and medical history.
Spirometry
The most common PFT that measures how much air you can inhale and exhale, and how quickly you can do so. It's the foundation for diagnosing obstructive lung diseases like asthma and COPD.
View MoreSpirometry with lung volumes
Combines spirometry with body plethysmography to measure total lung capacity, residual volume, and functional residual capacity. Essential for diagnosing restrictive lung diseases.
View MoreSpirometry with DLCO
Adds a diffusion capacity test to measure how efficiently oxygen passes from your lungs into your bloodstream. Critical for conditions like emphysema and interstitial lung disease.
View MoreSpirometry with bronchodilator reversibility
Involves repeating spirometry after administering a bronchodilator to assess if airway obstruction is reversible—key for distinguishing asthma from COPD.
View MoreSpirometry
The foundation of lung function testing
Spirometry is the most common and fundamental pulmonary function test. It measures how much air you can breathe in and out, and how quickly you can exhale. Using a device called a spirometer, the test captures key measurements that help diagnose and monitor respiratory conditions.
What spirometry measures:
- FVC (Forced Vital Capacity)Total air exhaled forcefully after maximum inhalation
- FEV1 (Forced Expiratory Volume in 1 Second)Air exhaled in the first second of forced expiration
- FEV1/FVC RatioKey indicator for obstructive vs restrictive disease
- PEF (Peak Expiratory Flow)Peak flow rate during forced exhalation
- FET (Forced Expiratory Time)Total time taken to exhale
When is spirometry recommended?
Doctors recommend spirometry for unexplained breathlessness, chronic cough, wheezing, chest tightness, to diagnose asthma or COPD, monitor existing lung conditions, assess fitness for surgery, and evaluate occupational lung exposure.
Spirometry with lung volumes
Complete lung capacity assessment
While spirometry measures airflow, it cannot measure the air that remains in your lungs after exhaling (residual volume). Spirometry with Lung Volumes uses body plethysmography—a specialized airtight chamber—to measure your complete lung capacity, including air that cannot be exhaled.
Additional measurements:
- TLC – Total Lung Capacity
- RV – Residual Volume
- FRC – Functional Residual Capacity
- RV/TLC – Air Trapping Ratio
When is it needed?
- •Diagnosing restrictive lung diseases
- •Assessing emphysema severity
- •Detecting air trapping in COPD
- •Evaluating interstitial lung disease
- •Pre-operative lung assessment
Spirometry with DLCO
Gas exchange & diffusion capacity
DLCO (Diffusing Capacity of the Lungs for Carbon Monoxide) measures how efficiently oxygen passes from your lungs into your bloodstream. While spirometry assesses airflow, DLCO evaluates the actual gas exchange function of your alveoli—the tiny air sacs where oxygen transfer occurs.
How DLCO works:
You'll inhale a small, safe amount of carbon monoxide (CO) mixed with a tracer gas, hold your breath for 10 seconds, then exhale. The equipment measures how much CO was absorbed by your lungs. Since CO binds to hemoglobin similarly to oxygen, this test reflects your lungs' ability to transfer oxygen.
When is DLCO essential?
Spirometry with bronchodilator reversibility
Distinguishing asthma from COPD
This test involves performing spirometry twice—before and after inhaling a bronchodilator medication (typically salbutamol). By comparing the results, doctors can determine if your airway obstruction is reversible, which is crucial for distinguishing between asthma and COPD.
The procedure:
Baseline spirometry is performed
You inhale a bronchodilator medication
Wait 15-20 minutes for medication effect
Repeat spirometry to measure improvement
What positive means:
A significant improvement after bronchodilator (≥12% AND ≥200ml increase in FEV1) suggests reversible obstruction.
Likely conditions
- AsthmaUsually shows good reversibility
- COPDShows partial or no reversibility
- Asthma-COPD OverlapMixed response
Conditions diagnosed using PFT
Pulmonary Function Tests help differentiate between obstructive and restrictive lung diseases, assess disease severity, and guide treatment decisions.
Obstructive diseases
Air has trouble flowing out of the lungs due to airway narrowing or obstruction
- Asthma
- COPD (Chronic Obstructive Pulmonary Disease)
- Chronic Bronchitis
- Emphysema
- Bronchiectasis
Restrictive diseases
The lungs cannot fully expand due to scarring, inflammation, or chest wall problems
- Pulmonary Fibrosis
- Interstitial Lung Disease (ILD)
- Sarcoidosis
- Chest Wall Deformities
- Neuromuscular Disorders
Other conditions
PFT helps evaluate various respiratory symptoms and conditions
- Post-COVID Respiratory Impairment
- Occupational Lung Diseases
- Pre-operative Assessment
- Unexplained Breathlessness
- Chronic Cough Evaluation
How to prepare for your PFT
Avoid smoking for at least 24 hours before the test
Avoid heavy meals 2 hours before testing
Stop bronchodilator medications as directed by your doctor
Avoid strenuous exercise for 30 minutes before the test
Wear loose, comfortable clothing
Bring a list of your current medications
Understanding PFT Parameters
A comprehensive guide to all parameters measured during pulmonary function testing, their normal values, and clinical significance.
Why choose Aelira for your PFT test in Delhi?
Expert Pulmonologists
Experienced specialists for accurate interpretation
Advanced Equipment
State-of-the-art, calibrated PFT machines
Same-Day Reports
Quick turnaround with detailed analysis
Complete Testing
Full range of PFT including DLCO & FOT
Ready to prioritize your lung health?
Book your PFT test today at Aelira Lung Health Centre in Green Park. Expert care, accurate results, and same-day reporting.