Percussion

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.