How to Identify Lung Sounds Caused by Asthma

Asthma is a chronic inflammatory disease involving the airways. During an asthma attack, narrowed breathing passages make it harder to breathe, which can cause a variety of sounds as you inhale and exhale.

Some sounds are loud enough that you can hear them on your own. A healthcare provider can detect others with a stethoscope. That's why listening to your lungs with a stethoscope is an important part of a physical examination.

Each type of sound can reveal something about your asthma and how well you're doing at the moment. This article will discuss various asthma lung sounds and what causes them.

Woman using an asthma inhaler

sigridgombert / Getty Images

Types of Asthma Lung Sounds

Asthma sounds are affected by the narrowing of the breathing passages. Both inflammation and mucus can contribute to the sounds made.

Expiratory Wheezing

Expiratory wheezing is something you hear as you exhale. It's a continuous, high-pitched whistling or purring sound.

Wheezing is generally loud enough to hear on your own. Your healthcare provider can also identify a wheeze by listening to your lungs through a stethoscope.

Expiratory wheezing means that your peak flow rate, which is the ability to push air out of your lungs, is lower than normal.

Inspiratory Wheezing

Inspiratory wheezing is a sound you hear as you inhale. It's a continuous noise that may be described as:

  • Whistling
  • Having a high pitch
  • Squeaking
  • Sounding musical

Stridor

Stridor is noisy, high-pitched breathing. It's similar to wheezing but tends to be louder and harsher. It might be described as turbulent airflow. It typically happens when you breathe in but can also happen when you breathe out. Stridor usually is not a feature of asthma.

Stridor occurs when there's an obstruction in the upper airway, which can be the result of an infection, inhaling an object, or other causes. Stridor is likely to be heard near your trachea and without a stethoscope.

Rhonchi

Rhonchi is typically lower pitched than a wheeze. It can sound like a rattle or have a musical quality. The sound is continuous as you inhale or exhale and can sound similar to snoring.

Rhonchi is caused by thickening mucus in the airways. You may be able to clear it by coughing.

Rales (Crackles)

Rales, or crackles, are intermittent, nonmusical sounds that may remind you of the sound of tearing Velcro.

There are two types of crackles. Fine crackles, which originate from the openings in the small airways, have a high pitch and are very brief. Coarse crackles, which come from air bubbles in the large bronchi, have a low pitch and last slightly longer than fine crackles.

Coughing

Coughing is a common symptom of asthma. And there's a type of asthma called cough-variant asthma, in which chronic coughing is the only symptom.

An asthma cough typically doesn't produce mucus. It's a dry cough that can be triggered by allergens, cold air, and exercise.

Other Symptoms of Asthma

Symptoms of asthma vary over time and in intensity. In addition to lung sounds such as wheezing, symptoms of asthma can include:

Treatment

There's no cure for asthma. The goal of treatment is to reduce exacerbations and manage symptoms. One key element is trying to identify and avoid triggers. Asthma treatment should be tailored to your needs and may include:

  • Bronchodilators relax muscles around the airways. They are available in long- and short-acting formulations. Short-acting medicines are known as rescue medicines.
  • Corticosteroids reduce swelling and lower the production of mucus in the airways.
  • Combination medicines both reduce swelling and mucus production and are a combination of bronchodilators and corticosteroids.
  • Anticholinergics prevent muscle bands from tightening around airways.

In most cases, you'll use an inhaler to take these medications.

If your asthma flares up due to a viral or bacterial infection, treatment may include antivirals or antibiotics.

When to See a Healthcare Provider

If your asthma is well-controlled, see your healthcare provider at least once a year. Give them a call if you have a worsening cough, wheezing, or other sounds outside your usual pattern. Signs you may need urgent medical attention are:

  • Lips or nails look blue.
  • Nostrils flare when you breathe.
  • Breathing rate is rapid.
  • You're having trouble walking or talking normally.
  • Your quick-acting treatment isn't working.

Diminished Lung Sounds

An asthma attack can diminish airflow. Sometimes, even with a stethoscope, your healthcare provider may have trouble hearing lung sounds as you breathe. This means you may not be getting enough air into your lungs. It can also mean you have a problem other than asthma, such as a buildup of fluid in or around the lungs.

Silent Chest

In a severe asthma attack, there can be such a significant reduction in air flow that there's no wheezing or any other sound heard when you breathe. A healthcare provider may not even be able to detect lung sounds with a stethoscope. This is a sign that you may need immediate treatment.

Silent Asthma

Silent asthma isn't a specific type of asthma. It means your asthma isn't causing coughing, wheezing, or other audible sounds. You may experience silent symptoms, such as chest tightness and shortness of breath. To make the diagnosis, your healthcare provider will likely order pulmonary function tests. These tests can determine if your breathing passages are narrowed and if your symptoms improve with medication.

Summary

Asthma lung sounds happen when there's inflammation or excess mucus in the airways. Narrowing of the airways can produce a variety of sounds as you inhale or exhale.

Some sounds are fairly loud and easy to hear. Others require a stethoscope. A healthcare provider can use these sounds, or a conspicuous lack of them, to gauge the severity of your condition.

There are several types of medicines to help manage asthma, as well as rescue medications you can use during an acute attack. Managing asthma should also involve identifying and avoiding allergens and other triggers.

A Word From Verywell

Living with asthma can be challenging, and severe asthma can lower your quality of life. You can help yourself by working closely with your healthcare team to keep your asthma well managed. Learn all you can about your triggers and how to avoid them.

Even if your asthma is currently under control, it's important to see your healthcare provider on a regular basis. Asthma can change over time, and your treatment plan may need periodic adjusting.

Frequently Asked Questions

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Seattle Children's Hospital. Asthma Attack.

  2. Nabi F, Sundaraj K, Lam C. Identification of asthma severity levels through wheeze sound characterization and classification using integrated power features. Biomedical Signal Processing and Control. 2019; 52:302-311. doi:10.1016/j.bspc.2019.04.018

  3. Pramono RXA, Bowyer S, Rodriguez-Villegas E. Automatic adventitious respiratory sound analysis: A systematic review. PLOS ONE. 2017;12(5):e0177926. doi:10.1371/journal.pone.0177926

  4. Kim Y, Hyon Y, Jung SS, et al. Respiratory sound classification for crackles, wheezes, and rhonchi in the clinical field using deep learning. Sci Rep. 2021;11(1):17186. doi:10.1038/s41598-021-96724-7

  5. Melbye H, Aviles Solis JC, Jácome C, Pasterkamp H. Inspiratory crackles-early and late-revisited: identifying COPD by crackle characteristicsBMJ Open Respir Res. 2021;8(1):e000852. doi:10.1136/bmjresp-2020-000852

  6. Harvard Health Publishing. That nagging cough.

  7. MedlinePlus. Breath Sounds.

Additional Reading

By Ann Pietrangelo
Ann Pietrangelo is a freelance writer, health reporter, and author of two books about her personal health experiences.