Percussion

Percussion

Percussion involves tapping on a surface to evaluate the underlying structure and is a key component of clinical examinations to assess the thorax or abdomen. It is among the four primary methods of clinical examination, alongside inspection, palpation, and auscultation.

Performed with the middle finger of one hand tapping on the other middle finger using a wrist action, percussion is applied firmly over tissue rather than bone. When percussing bony areas like the clavicle, the stationary finger may be omitted, and the bone is tapped directly, as seen when assessing an apical cavitary lung lesion common in TB.

There are two types of percussion: direct, utilizing one or two fingers, and indirect, employing the middle or flexor finger. Percussion yields four distinct sounds: resonant, hyper-resonant, stony dull, or dull. A dull sound indicates the presence of a solid mass beneath the surface, while a more resonant sound suggests hollow, air-containing structures. Additionally, these sounds produce varying sensations in the finger used to percuss.

Historically, percussion was utilized to differentiate between empty and filled barrels of liquor, a technique introduced to medicine by Dr. Leopold Auenbrugger.

Percussion of the Thorax

This method aids in diagnosing conditions such as pneumothorax, emphysema, and other thoracic diseases, while also evaluating respiratory mobility.

Percussion of the Abdomen

Used to detect organ enlargement (organomegaly), abdominal percussion relies on setting tissue and spaces in between into vibration. The resulting sound helps determine the tissue's health status.

Percussion Notes

Auditory and tactile perceptions classify the notes heard into categories such as:

 • Tympanic or tympanitic, resembling drum-like sounds heard over air-filled structures during abdominal examinations.
 • Hyperresonant (indicative of pneumothorax)
 • Normal resonance/Resonant
 • Impaired resonance (suggestive of mass or consolidation)
 • Dull (associated with consolidation)
 • Stony dull (a specific test)