Percussion is a method of tapping body parts with fingers, hands, or small instruments as part of a physical examination. It is done to determine:
- The size, consistency, and borders of body organs
- The presence or absence of fluid in body areas
Percussion of a body part produces a sound, like playing a drum. The sound is a sign of the type of tissue within the body part or organ.
- Lungs sound hollow on percussion because they are filled with air.
- Bones, joints, and solid organs such as the liver sound solid.
- The abdomen sounds like a hollow organ filled with air, fluid, or solids.
Swartz MH. The physical examination. In: Swartz MH, ed. Textbook of Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 4.