Heart & Lung Auscultation Sites: Where to Place the Stethoscope

An anatomy guide for the cardiac and respiratory exam · Updated 2026

Placing the stethoscope in the wrong spot is the fastest way to miss a finding. Each valve projects its sound to a specific area of the chest wall, and each lung field tells you about a different part of the lungs. Here's the map.

The four cardiac auscultation areas

Remember the order with "APT M" — All Physicians Take Money — moving top-right to bottom-left:

Note the areas are named for where sound is best heard, not where the valve sits anatomically — blood carries the sound downstream.

The lung fields

Auscultate systematically, comparing left to right at each level, front and back:

• Anterior upper (near clavicles) and anterior lower fields.
• Posterior fields — the bases posteriorly are where dependent crackles of edema and consolidation show first.
• Lateral / mid-axillary — the right middle lobe and lingula are best caught here.

One full breath through the mouth at each spot, diaphragm on skin, side-to-side comparison — asymmetry is often the most important finding.

Bell vs diaphragm

The diaphragm (pressed firmly) captures high-frequency sounds: most murmurs, breath sounds, S1/S2. The bell (light touch) captures low-frequency sounds: S3, S4 and mitral stenosis. Pressing the bell hard turns it into a diaphragm and filters those low sounds out — a classic reason students miss a gallop.