Body Plethysmography in Delhi | Lung Volume Test Specialist

Body Plethysmography

Body Plethysmography is an advanced lung function test which measures the total volume of the lungs, including the air that remains in your lungs after you breathe out. This test captures the entire capacity of your lungs. It is often performed inside an airtight glass cabin which looks like a phone booth, and is sometimes simply called a lung box test.

Why is it done?

It is performed for:

Diagnosing or monitoring the restrictive lung diseases like pulmonary fibrosis or scoliosis.
Detecting the air trapping and lung hyperinflation in asthma or COPD.
Evaluating the lung volume changes after surgery or in obesity.
Assessing neuromuscular diseases that affect your breathing.
Guiding the treatment in complex or mixed lung conditions.

Symptoms

Persistent shortness of breath
Chronic cough
Fatigue or reduced exercise tolerance
An abnormal chest X-ray or CT scan
Inconclusive spirometry results

How to Prepare

You should avoid smoking or using inhalers before the test (unless advised otherwise).
Wear loose and comfortable clothing.
Avoid having heavy meals before the testing.
You should inform the technician if you feel claustrophobic, dizzy, or anxious.

How the Test is done?

You have to sit in a sealed glass cabin and breathe through a mouthpiece while wearing a nose clip.
The technician will guide you to breathe in different patterns i.e. normal, deep, and quick breaths.
Then the machine will track the changes in pressure and airflow as you breathe.
It calculates lung volumes by applying Boyle’s Law, which relates pressure and volume in a closed space.
The test takes about 15–20 minutes and is completely non-invasive.

What It Measures

TLC (Total Lung Capacity) – The total amount of air the lungs can hold.
RV (Residual Volume) – Amount of air remaining after full exhalation.
FRC (Functional Residual Capacity) – Air left after normal exhalation.
VC (Vital Capacity) – Air expelled after full inhalation.
ERV/IRV – Extra air you can breathe in or out voluntarily.

Frequently Asked Questions (FAQs)

1. Is the test uncomfortable or painful?

No, it’s completely painless. You’ll be kept inside a small cabin, which might feel tight, but it’s quick and safe.

2. What’s the difference between spirometry and body plethysmography?

Spirometry measures airflow, while plethysmography measures air volume. It provides more detailed information, especially about air trapping and lung stiffness.

3. Who should not do this test?

People with severe claustrophobia, unstable heart disease, or recent surgeries should inform their doctor before the testing.

4. Do I need to repeat this test regularly?

If you have a chronic lung condition, then this test might be repeated every 6–12 months to monitor the disease progression or treatment response.

Body Plethesmography