A stethoscope is an important diagnostic tool that allows a nurse or physician to listen to heart and respiratory sounds. Using a stethoscope one can discern the presence of a heart murmur. When listening to the lungs with a stethoscope, a nurse or physician can diagnose diseases such as asthma, pneumonia, congestive heart failure, or collapsed lungs.

Medical professionals also use a stethoscope to record a person’s blood pressure (BP) by listening to the flow of blood through the patient’s arteries.