Best Pulmonary Function Test (PFT) in Hyderabad at Dr. Raju's Allergy Centre & Multispeciality Hospital

What is a Pulmonary Function Test (PFT)?

A Pulmonary Function Test (PFT) is a comprehensive evaluation of how well your lungs are working. It measures lung capacity, volume, gas exchange, and airflow to assess overall respiratory health. These tests help determine how much air your lungs can hold, how quickly you can move air in and out of your lungs, and how efficiently your lungs transfer oxygen into your bloodstream.

PFTs are essential tools in diagnosing and managing various respiratory conditions. They provide objective data about lung function that cannot be obtained through physical examination alone. At Dr. Raju's Allergy Centre, we offer complete pulmonary function testing to evaluate patients with respiratory symptoms, monitor disease progression, and assess response to treatment.

A full PFT typically includes three main components: spirometry, lung volume measurement (plethysmography), and diffusing capacity of the lungs for carbon monoxide (DLCO). Each component provides different information about lung health and helps identify specific patterns of respiratory disease.

Why is Pulmonary Function Testing Important?

• Accurate Diagnosis: Differentiates asthma, COPD, pulmonary fibrosis, and other respiratory disorders
• Disease Severity Assessment: Quantifies impairment and classifies severity
• Treatment Monitoring: Serial PFTs track progression and response to medications
• Pre-Operative Evaluation: Assesses surgical risk for chest or abdominal surgery
• Disability Evaluation: Provides objective data for insurance or legal purposes
• Occupational Lung Disease Screening: Monitors workers exposed to pulmonary toxins

Common Indications for PFT

• Unexplained shortness of breath or difficulty breathing
• Chronic cough (lasting more than 3 weeks)
• Wheezing or chest tightness
• Excessive mucus production
• Decreased exercise tolerance
• Known respiratory condition requiring monitoring (asthma, COPD, ILD)
• Pre-operative assessment before major surgery
• Exposure to occupational lung hazards
• Monitoring medication effects on lungs
• Evaluating response to pulmonary rehabilitation

Types of Pulmonary Function Tests

1. Spirometry

Spirometry is the most common and fundamental PFT. It measures how much air you can exhale and how quickly. Essential for diagnosing obstructive lung diseases like asthma and COPD.

How It Works: You breathe into a mouthpiece connected to a spirometer; after a deep breath, you exhale forcefully and as quickly as possible; the device records volume and flow rate over time; repeated for consistency; often performed before and after bronchodilator to assess reversibility.

Key Measurements: FVC (Forced Vital Capacity), FEV1 (Forced Expiratory Volume in 1 second), FEV1/FVC ratio (reduced = obstruction), PEF (Peak Expiratory Flow), FEF 25–75% (sensitive for small airway disease)

2. Lung Volume Measurement (Plethysmography)

Assesses total lung capacity and volumes remaining after different phases of breathing. The most accurate method is body plethysmography.

How It Works: You sit inside a sealed transparent box (plethysmograph); you breathe through a mouthpiece while pressure changes are measured; pressure changes allow calculation of all lung volumes including trapped air. Alternative: gas dilution (helium)—less accurate for trapped air.

Key Measurements: TLC (Total Lung Capacity), RV (Residual Volume), FRC (Functional Residual Capacity), VC (Vital Capacity)

3. Diffusing Capacity (DLCO)

Measures how efficiently oxygen moves from lungs into the bloodstream. Carbon monoxide is used as a tracer gas.

How It Works: You inhale a small, safe amount of CO mixed with tracer gas; hold breath for 10 seconds; exhale; the difference between inhaled and exhaled CO indicates gas transfer across the alveolar membrane.

Clinical Significance: Low DLCO: emphysema, pulmonary fibrosis, pulmonary hypertension, anaemia. High DLCO: asthma, cardiac shunts, alveolar haemorrhage.

4. Bronchodilator Responsiveness Testing

Determines whether airflow obstruction is reversible (characteristic of asthma). Spirometry before and 15–20 minutes after bronchodilator. Positive response: FEV1 and/or FVC increase ≥12% AND ≥200 mL from baseline.

5. Maximal Voluntary Ventilation (MVV)

Measures maximum air breathed in and out over 15–30 seconds. Assesses respiratory muscle strength and endurance. Decreased in neuromuscular disorders, obstructive and restrictive diseases.

6. Bronchoprovocation Testing (Methacholine Challenge)

Used when asthma is suspected but routine spirometry is normal. You inhale increasing doses of methacholine; spirometry repeated after each dose. Significant drop in FEV1 indicates airway hyperresponsiveness, supporting asthma diagnosis.

Understanding PFT Results

Results are compared to predicted values based on age, height, sex, and ethnicity. Modern guidelines recommend z-scores for accurate interpretation.

Obstructive Pattern: FEV1/FVC decreased; TLC normal or increased; RV often increased (air trapping). Typical: Asthma, COPD, bronchiectasis.

Restrictive Pattern: TLC decreased; FVC decreased; FEV1/FVC normal or increased. Typical: Pulmonary fibrosis, ILD, chest wall deformities, obesity, neuromuscular weakness.

Mixed Pattern: FEV1/FVC decreased and TLC decreased. Typical: COPD with restriction, silicosis, certain ILD with airway involvement.

DLCO Interpretation

How to Prepare for a Pulmonary Function Test

Before the Test: Medication adjustments (you may need to stop certain inhalers—your doctor will advise); avoid heavy meals; no smoking 4–6 hours before; no caffeine on test day; wear loose clothing; bring medication list; inform doctor of recent respiratory infection.

What to Bring: Doctor's referral or prescription, insurance information, previous PFT results if available, list of questions.

What to Expect During the Test

You will be seated; a nose clip ensures mouth-only breathing; you breathe through a sterile mouthpiece; the technician guides each maneuver; multiple efforts ensure reproducibility. Session typically 60–90 minutes. You may experience temporary shortness of breath or lightheadedness from forceful breathing; mild discomfort from mouthpiece or nose clip; the plethysmograph may feel confining but is brief.

Risks and Contraindications

Relative Contraindications: Recent heart attack, uncontrolled hypertension, recent eye/chest/abdominal surgery, pneumothorax, aortic aneurysm, active respiratory infection, hemoptysis, recent stroke.

Potential Risks: Temporary shortness of breath, lightheadedness, coughing, minor discomfort; extremely rare: pneumothorax. Our facility is fully equipped and testing is supervised by experienced personnel.

Why Choose Dr. Raju's Allergy Centre for Pulmonary Function Testing?

• Specialised Expertise: Deep understanding of respiratory physiology and test interpretation
• State-of-the-Art Equipment: Advanced spirometry, plethysmography, and DLCO systems
• Experienced Technicians: Skilled personnel for patient comfort and reproducible results
• Comprehensive Testing: Pre/post bronchodilator, lung volumes, diffusion capacity
• Child-Friendly Approach: Experience testing children and adults
• Integrated Care: Results inform treatment for asthma, COPD, and other conditions
• Clear Communication: Results explained with practical next steps

Interpreting Your Results

Dr. Raju CH will: review all measurements; compare to reference values; identify obstructive, restrictive, or mixed patterns; assess severity; evaluate bronchodilator response; correlate with symptoms; develop a treatment plan; schedule follow-up as needed.

Frequently Asked Questions About PFT

Is the test painful? No. Mild discomfort from forceful breathing may occur; tests are generally well-tolerated.

How long does the test take? Full PFT: 60–90 minutes. Spirometry alone: 30–45 minutes.

Do I need a referral? Yes. Bring your prescription or referral.

Can I take medications before? Some (e.g. bronchodilators) may need to be withheld. Your doctor will advise.

How often should PFTs be repeated? Asthma: annually or as needed; COPD: annually; ILD: every 3–6 months; pre-operatively as scheduled.

Can children have PFTs? Yes, children 5–6 years and older can typically perform spirometry with coaching.

Insurance coverage? Most plans cover medically necessary PFTs. Our staff can assist with pre-authorisation.

Conditions Diagnosed or Monitored with PFT

• Asthma, COPD, Interstitial Lung Disease, Pulmonary Fibrosis, Bronchiectasis
• Neuromuscular disorders (respiratory muscle weakness)
• Pre-operative assessment, Occupational lung disease

"Pulmonary function testing provides objective, quantifiable data about lung health that is essential for accurate diagnosis and effective management of respiratory diseases. When interpreted by an experienced specialist, these tests guide treatment decisions and help patients achieve better outcomes."