What is the purpose of percussion in a physical assessment?

Percussion is a technique used in physical assessments primarily to evaluate the underlying structures and organ size. It involves tapping the body lightly with the fingertips or a percussion hammer to produce sounds that help assess the density of the underlying tissues. Different sounds can indicate whether structures are solid, fluid-filled, or air-containing, thus offering valuable information about the size and condition of organs.

For example, when assessing the lungs, a healthcare provider can determine if there is fluid present in the pleural space or if the lungs are obstructed. Similarly, when examining the abdomen, percussion can provide insights regarding the size of organs like the liver or spleen, determining if they are enlarged or if there are any abnormalities present.

The other options do not relate to the primary purpose of percussion in assessments. Diagnosing mental health disorders typically involves different assessment techniques such as interviews or psychological testing. Measuring blood pressure requires the use of a sphygmomanometer and is not related to the percussion technique. Observing external physical features involves visual inspection and palpation rather than percussion. Thus, the choice that emphasizes the evaluation of organ size and underlying structures aligns precisely with the purpose of percussion in a physical assessment.