It’s the most iconic medical doctor symbol. It’s been around doctors’ necks and tucked in their pockets for over 200 years. It’s the stethoscope. This medical device proliferates all doctor iconography, from costumes to emojis to TV personalities. We have all seen a stethoscope and have had experience with it; but, what does it do?

In short, the stethoscope helps amplify internal body sounds from the heart, lungs, and bowls. Each internal sound has a “normal” frequency range that doctors listen for.

Since its first introduction to the medical world, the stethoscope has evolved in technology and what doctors look for when they listen. Today, some stethoscopes are equipped with EKG technology that allows your doctors to view your heart rate while listening to it simultaneously.

There are also electronic stethoscopes that amplify sound and utilize noise-canceling technology so your physician can hear your heart more clearly. Furthermore, as doctors identify more diseases and biological complications, they can use this seemingly niche tool for various diagnostic measures.

Within minutes of listening to you “take a deep breath in,” doctors can hear for abnormalities that may indicate if you need emergency attention, thus saving your life. Five abnormalities they can identify with the stethoscope include:

A narrow valve: Each valve has a specific murmur sound. Doctors will hear the murmur and identify which valve is having trouble. Then, they’ll determine the severity of the problem. 

Valve leakage: Physicians can identify a leaky valve with a “whooshing” sound instead of the “thud, thud” of a healthy heartbeat. Different “whooshes” between “thuds” can help doctors identify which valve is leaking and how much blood is escaping.

Arrhythmias or “abnormal heart rhythm:” The abnormal rhythm doctors are listening for can indicate if your heart is beating too slow, fast, or irregular.

Fluid in the lungs: Doctors listen for absent or decreased breath sounds to determine if you have fluid blocking your breathing, which can be caused by pneumonia, heart failure, and pleural effusion.

Rhonchi, a snoring-like sound: This sound occurs when air is blocked or inhibited through your large airways. Rhonchi could indicate whether the patient has asthma, pneumonia, chronic bronchitis, or cystic fibrosis.

It’s amazing what doctors can hear with one breath in and one out. Your doctors are listening to your heart, and you should too!