Wheezing
Wheezing is a high-pitched whistling sound during breathing. It occurs when air moves through narrowed breathing tubes in the lungs.
What causes wheezing? - Animation
Wheezing can be a normal healthy response to an unhealthy environment. Or, wheezing can be a sign of asthma. I'm Dr. Alan Greene and I want to talk with you for a moment about how to tell the difference, what causes wheezing anyway, and when is it healthy and when is it not. Well to understand that, first let's all take a deep breath together (inhales). When you breathe in, the air comes through your nose or mouth, through the big windpipe and breaks into 2 big bronchi, one into each lung. And from there they break into a whole bunch of little, smaller bronchioles. It's almost like a tree's branches branching out. And those bronchioles are where the wheezing happens. Let's look at a bronchiole. Here's one of those small airways. Now if you happen to walk into a cloud of something that's toxic, your body is going to respond instantly to try to protect you. The first thing that will happen is the muscles around the bronchioles will tighten, will constrict down almost like a boa constrictor, and you get the tight airways. If that toxic cloud is still there, to protect your delicate tissues deep in your lungs, swelling of the lining will happen. Inflammatory stuff to help protect you from those toxins. And if it's still there, still irritating, mucus will begin to be secreted to be able again to capture and protect you from those toxins. That's wheezing. Asthma happens when your airways are hyper-responsive. When they're twitchy. When they're hyper-alert and they respond to something that's not truly dangerous. The problem with that is when your bronchioles are constricted and swollen and has mucus in them, that narrow little opening is hard to breathe through. You have to work to breathe, especially to breath out. And that hard breathing through a narrow passageway is what creates the sound we know as wheezing.
Considerations
Wheezing is a sign that a person may be having breathing problems. The sound of wheezing is most apparent when breathing out (exhaling). It may also be heard when breathing in (inhaling).
Wheezing most often comes from the small breathing tubes (bronchial tubes) deep in the lungs. But it may be due to a blockage in larger airways or in people with certain vocal cord problems.
Lungs
The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.
Causes
Causes of wheezing may include any of the following:
- Asthma
Asthma
Asthma is a chronic disease that causes the airways of the lungs to swell and narrow. It leads to breathing difficulty such as wheezing, shortness o...
Read Article Now Book Mark Article - Breathing a foreign object into the airways to the lungs
- Damage and widening of the large airways in the lungs (bronchiectasis)
Bronchiectasis
Bronchiectasis is a disease in which the large airways in the lungs are damaged. This causes the airways to become permanently wider. Bronchiectasis...
Read Article Now Book Mark Article - Swelling and mucus buildup in the smallest air passages in the lungs (bronchiolitis)
Bronchiolitis
Bronchiolitis is swelling and mucus buildup in the smallest air passages in the lungs (bronchioles). It is usually due to a viral infection....
Read Article Now Book Mark Article - Swelling and mucus buildup in the main passages that carry air to the lungs (bronchitis)
Bronchitis
Acute bronchitis is swelling and inflamed tissue in the bronchi, the main passages that carry air to the lungs. This swelling narrows the airways, w...
Read Article Now Book Mark Article - Chronic obstructive pulmonary disease (COPD), especially when a respiratory infection is present
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is a common lung disease. Having COPD makes it hard to breathe. There are two main forms of COPD:Chroni...
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Acid reflux disease
Gastroesophageal reflux disease (GERD) is a condition in which the stomach contents leak backward from the stomach into the esophagus (food pipe). F...
Read Article Now Book Mark Article - Heart failure (cardiac asthma)
- Insect sting that causes an allergic reaction
Allergic reaction
Allergic reactions are sensitivities to substances called allergens that come into contact with the skin, nose, eyes, respiratory tract, and gastroin...
Read Article Now Book Mark Article - Certain medicines (such as aspirin)
- Infection of the lungs (pneumonia)
Pneumonia
Pneumonia is a breathing (respiratory) condition in which there is an infection of the lung. This article covers community-acquired pneumonia (CAP). ...
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- Viral infection, especially in infants younger than age 2
Asthmatic bronchiole and normal bronchiole
Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, mucus production is increased, muscles of the bronchial tree become tight, and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound.
Home Care
Take all of your medicines as directed.
Sitting in an area where there is moist, heated air may help relieve some symptoms. This can be done by running a hot shower or using a vaporizer.
When to Contact a Medical Professional
Contact your health care provider if wheezing:
- Occurs for the first time
- Occurs with significant shortness of breath, bluish skin, confusion, or mental status changes
Shortness of breath
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
Read Article Now Book Mark ArticleBluish skin
A bluish color to the skin or mucous membrane is usually due to a lack of oxygen in the blood. The medical term is cyanosis.
Read Article Now Book Mark ArticleConfusion
Confusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...
Read Article Now Book Mark Article - Keeps occurring without explanation
- Is caused by an allergic reaction to a bite or medicine
If wheezing is severe or occurs with severe shortness of breath, you should go directly to the nearest emergency department.
What to Expect at Your Office Visit
Your provider will perform a physical exam and ask about your medical history and symptoms. Questions about your wheezing may include when it started, how long it has lasted, when it is worse, and what might have caused it.
The physical exam may include listening to the lung sounds (auscultation). If your child has the symptoms, their provider will make sure your child didn't swallow a foreign object.
Auscultation
Auscultation is listening to the sounds of the body during a physical examination.
Read Article Now Book Mark ArticleTests that may be done include:
- Blood tests, possibly including arterial blood gases
Arterial blood gases
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
Read Article Now Book Mark Article - Chest x-ray
Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
Read Article Now Book Mark Article - Lung function tests
Lung function tests
Pulmonary function tests are a group of tests that measure breathing and how well the lungs are functioning.
Read Article Now Book Mark Article - Pulse oximetry to measure blood oxygen level
A hospital stay may be needed if:
- Breathing is particularly difficult
- Medicines need to be given through a vein (IV)
- Supplemental oxygen is required
- The person needs to be closely watched by medical personnel
Reviewed By
Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Doss AMA, Stokes JR. Viral infections and wheezing in preschool children. Immunol Allergy Clin North Am. 2022;42(4):727-741. PMID: 36265972 pubmed.ncbi.nlm.nih.gov/36265972/.
Kliegman RM, St. Geme JW, Blum NJ, et al. Wheezing, bronchiolitis, and bronchitis. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 439.
Woodruff PG, Bhakta NR, Ortega VE, Lambrecht BN, Fahy JV. Asthma: pathogenesis and phenotypes. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 60.