Lung Sounds: What Do They Mean?

If your doctor thinks you might have an issue with your lungs, the type and location of certain breathing sounds can help them figure out what might be behind it.

Wheezing

This high-pitched whistling noise can happen when you’re breathing in or out. It’s usually a sign that something is making your airways narrow or keeping air from flowing through them.

Two of the most common causes of wheezing are lung diseases called chronic obstructive pulmonary disease (COPD) and asthma. But many other issues can make you wheeze, too, including:

• Allergies
• Bronchitis or bronchiolitis
• Emphysema
• Epiglottitis (swelling of the top flap of your windpipe)
• Gastroesophageal reflux disease (GERD)
• Heart failure
• Lung cancer
• Sleep apnea
• Pneumonia
• Respiratory syncytial virus (RSV)
• Vocal cord problems
• An object stuck in your voice box or windpipe

You can also start wheezing if you smoke or as a side effect of some medications. It’s not always serious, but if you have trouble breathing, are breathing really fast, or your skin turns a bluish color, see your doctor.

If you start wheezing suddenly after an insect bite or after eating food you may be allergic to, go to the emergency room right away.

Crackling (Rales)

This is a series of short, explosive sounds. They can also sound like bubbling, rattling, or clicking. You’re more likely to have them when you breathe in, but they can happen when you breathe out, too.

You can have fine crackles, which are shorter and higher in pitch, or coarse crackles, which are lower. Either can be a sign that there’s fluid in your air sacs.

They can be caused by:

• Pneumonia
• Heart disease
• Pulmonary fibrosis
• Cystic fibrosis
• COPD
• Lung infections, like bronchitis
• Asbestosis, a lung disease caused by breathing in asbestos
• Pericarditis, an infection of the sac that covers your heart

Stridor

This harsh, noisy, squeaking sound happens with every breath. It can be high or low, and it’s usually a sign that something is blocking your airways. Your doctor can typically tell where the problem is by whether your stridor sounds happen when you breathe in or out. It’s not always serious, but it sometimes can be a sign of a life-threatening problem that needs medical attention right away.

You may get stridor if you have:

• Laryngomalacia(softening of the vocal cords in babies)
• Paralyzed vocal cord
• Narrow voice box
• Unusual growth of blood vessels (hemangioma) just below your vocal cords
• Croup
• Infection of your trachea (windpipe)
• Epiglottitis (when the “lid” of cartilage that covers your windpipe swells and blocks the flow of air to your lungs)

You can also have stridor if an object gets stuck in your windpipe. You might need surgery to fix that problem.

Rhonchi

These low-pitched wheezing sounds sound like snoring and usually happen when you breathe out. They can be a sign that your bronchial tubes (the tubes that connect your trachea to your lungs) are thickening because of mucus.

Rhonchi sounds can be a sign of bronchitis or COPD.

Whooping

This high-pitched gasp typically follows a long bout of coughing. If you hear a “whoop” when you breathe in, it may be a symptom of whooping cough (pertussis), a contagious infection in your respiratory system.

Pleural Friction Rub

The membranes that cover the walls of your chest cavity and the outer surface of your lungs are called pleura. If they get inflamed and rub together, they can make this rough, scratchy sound.

It can be a sign of pleurisy (inflammation of your pleura), pleural fluid (fluid on your lungs), pneumonia, or a lung tumor.

Mediastinal Crunch

This sound, also called Hamman’s sign, tells your doctor that air is trapped in the space between your lungs (called the mediastinum). It’s a crunchy, scratchy sound, and it happens in time with your heartbeat. That’s because your heart movements shift the trapped air and cause the scratching sounds.

These crunching sounds can sometimes mean you have a collapsed lung, especially if you also have chest pain and shortness of breath. They also can be a sign of lung disease like COPD, pneumonia, or cystic fibrosis.

Tests

Your doctor can get important information about the health of your lungs by listening closely as you breathe. The easiest and most common way to do this is to hold a stethoscope to the skin on your back and chest. This is called auscultation.

As your doctor listens, they’ll ask you to take deep breaths through your mouth. They also may ask you to speak certain phrases and see how they sound through your chest or back. Some examples of this include:

• Bronchophony: Your doctor will ask you to say “ninety-nine.” Normally, your lungs will muffle the words. If the words sound clear through the stethoscope, it may be a sign that your lungs are filled with blood, fluid, or mucus.
• Whispered pectoriloquy: This involves whispering “ninety-nine” or “one, two, three.” Healthy lungs will dampen the sound and make the words faint, but they’ll be louder if your lungs are filled with fluid.
• Egophony: If you have fluid in your lungs, your doctor uses this test to check for a collapsed lung. As you say an “e” sound, your doctor will listen to see if it’s muffled and sounds like “e” or if it’s louder and sounds like “a,” which means fluid is changing the sound.