Chest percussion: resonance, dullness and hyperresonance !

Exam technique

Tapping the chest makes a sound that changes when air, fluid or solid tissue lies underneath.

Updated 2026-11-01

See it in 3D: Diaphragm · Ribs (back part)

What it is

Percussion compares the sound made by tapping over different lung fields. Healthy air-filled lung is resonant; fluid or solid tissue sounds dull, and excess air sounds hyperresonant. Percussion also outlines the lung bases and measures diaphragmatic excursion.

Landmark anatomy

The sound depends on the ratio of air to tissue beneath the finger, only a few centimetres deep.
On the right front, lung resonance turns dull over the liver, around the fifth intercostal space in the midclavicular line.
On the left, below the costal margin, the gas-filled stomach gives tympany (Traube space).
The costodiaphragmatic recess is where pleural fluid collects first in the upright position.

Technique, step by step

Seat the patient with arms crossed in front to move the scapulae aside when percussing the back.
Press the middle finger of the non-dominant hand firmly on an intercostal space, with the palm off the wall.
With the tip of the other middle finger, strike the middle phalanx once or twice using the wrist, not the arm.
Lift the striking finger at once so the sound is not damped.
Percuss from apices to bases, alternating sides at symmetric points, behind, at the sides and in front.
Find the base: the point on the back where resonance turns dull, with the patient in expiration.
Ask for a held deep breath, find the border again and measure the distance: this is diaphragmatic excursion.

Abnormal findings

Basal dullness with an upper border that rises toward the axilla: pleural effusion; just above it there may be a band of increased resonance.
Localized dullness with increased fremitus: consolidation.
One-sided hyperresonance with absent breath sounds: pneumothorax.
Bilateral hyperresonance with low, poorly moving bases: hyperinflation (COPD, severe asthma).
A high base on one side with little excursion: diaphragm paralysis, atelectasis or a subdiaphragmatic mass.

Common errors

Striking hard or with the palm resting on the wall damps the note and blurs dull and resonant.
Percussing over ribs or scapula instead of intercostal spaces.
Small effusions and deep lesions do not change percussion; ultrasound and radiographs detect them better.

Test yourself

Think of the answer, then tap the question to see it.

What percussion note is expected in pneumothorax?

Hyperresonance or tympany on the affected side, with reduced or absent breath sounds.

How is diaphragmatic excursion measured?

Mark the posterior lung base at full expiration and again at full inspiration; the distance between the two points is the excursion.

What causes tympany below the left costal margin?

The gas-filled stomach (Traube space); its loss may be seen with a left effusion or splenomegaly.

What note does a pleural effusion give and how is it told from consolidation?

Marked basal dullness; in effusion fremitus and breath sounds fall, while in consolidation fremitus rises and bronchial breathing appears.

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See it in 3D

The structures of Durgical's 3D anatomy where it is found.

← All of the clinical exam

Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.

Sources: Pleural effusion: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2024); Collapsed lung (pneumothorax) (MedlinePlus, U.S. National Library of Medicine, 2024); Community-acquired pneumonia in adults: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2024).

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Representative model, for educational purposes only.