Percussion (medicine)

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Percussion is a method used by a doctor to find out about the changes in the thorax or abdomen. It is done by tapping on a surface to determine the underlying structure. It is one of the four methods of clinical examination: inspection, palpation, percussion and auscultation. It is done with the middle finger of right hand tapping on the middle finger of the left hand, which is positioned with the whole palm on the body.

There are two types of percussion: direct percussion, which uses only 1 or two fingers, and indirect percussion, utilizing the middle/flexor finger. The method was initially used to distinguish between empty and filled barrels of liquor.

There are four different percussion sounds:

sonorous
hypersonorous
relatively dull sound
completely dull sound

The presence of a solid mass underneath the surface will produce a dull sound. Hollow, air-containing structures will lead to a more sonore sound.

[edit] Percussion of the thorax

It is used to diagnose pneumothorax, emphysema and other diseases. It can be used to access the respiratory mobility of the thorax.

[edit] Percussion of the abdomen

It is used to find whether any organ is enlarged and similar. It is based on the principle of setting tissue and spaces in between at vibration. The sound thus generated is used to determine if the tissue is healthy or pathological.