ELI5: What is ghost murmur and how it works?

Ghost murmur is a normal, quiet breathing sound you can hear with a stethoscope over most of your lungs.

Imagine you're blowing gently on a piece of paper held a little way from your mouth. You can hear a soft "whoosh" sound, right? That's kind of like ghost murmur. It's the sound of air moving in and out of the tiny air sacs, called alveoli, in your lungs.

Think of your lungs like a big tree.

• The trachea (windpipe) is like the trunk.
• The bronchi (big tubes) are like the main branches.
• The bronchioles (smaller tubes) are like the smaller branches.
• The alveoli (air sacs) are like the tiny leaves at the end of all the branches.

Doctors use a stethoscope to listen to your lungs, just like listening for the "whoosh" sound of the air moving. They listen for:

• The presence of the ghost murmur to make sure the air is getting everywhere it needs to go.
• How loud or quiet the murmur is because changes in loudness can mean something is wrong.
• If there are any extra sounds, like wheezing or crackling, which could mean there's a problem like asthma or pneumonia.