Glossary

Crackles

Crackles

Rasselgeräusch

Crackles are additional lung sounds that become audible when listening with a stethoscope. They indicate fluid or mucus in the airways, for example in pneumonia or heart failure.

Symptoms rather than terms?

Describe what's going on — we'll find the right doctor for you.

Editorial content · as of 9/5/2026