Overview of Wheezing Breaths

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Wheezing is a common but frightening symptom in which there is a high-pitched whistling sound that occurs with breathing. It may occur alone or with other symptoms such as shortness of breath. There are many possible causes, ranging from asthma to severe allergic reactions, and from heart disease to acid reflux. It's important to distinguish wheezing from stridor, another serious symptom that often has a different music pitch and is caused by different conditions, though both conditions can be life-threatening. There are a number of tests that may be done to diagnose the condition, and an accurate diagnosis is needed to choose the best treatment.

woman wheezing


Wheezing can occur both with breathing in (inspiratory wheezing) and with breathing out (expiratory wheezing), though it is more common with breathing out. While many people—and healthcare providers as well—think of asthma when they hear wheezing, it's important to note that "all that wheezes is not asthma" and these other causes must be ruled out before assuming a diagnosis of asthma.

In addition to other causes of wheezing, sometimes people have more than one condition which leads to wheezing. That's a long-winded way of saying that anyone who has wheezing should have a very careful evaluation of their symptoms.


Before talking about wheezing, it's important to know whether the sounds you hear in your lung are truly wheezing. Why? Because there are other sounds that can be mistaken for wheezing and making an accurate assessment can be critical in finding the causes.

Healthcare providers use the term auscultation to describe the process of listening to the lungs for the presence or absence of "normal" lung sounds as well as any sounds that are not ordinarily heard.

Wheezing vs. Stridor

Stridor is a symptom that is often mistaken for wheezing. This is important because there are a few causes of stridor that are serious medical emergencies.

Stridor has a sound that is usually monophonic—meaning that only one note is heard rather than a variety of musical notes. Stridor tends to be higher in pitch than the sounds due to wheezing and occurs predominately during inspiration. Stridor is usually loudest over the anterior neck, whereas wheezing can be loudest in different regions over the lungs, depending on which airways are most affected.

Unlike stridor, wheezing is often a medium pitched sound which is loudest during expiration. It has a fairly continuous musical sound including more than one note.

The sound of wheezing is created by a narrowing of the airways. This can be due to swelling or blockage anywhere from the throat down to the smallest airways.


The most common causes of wheezing are asthma and COPD, but as noted, there are many potential causes including:

  • Asthma: The most common cause of wheezing is asthma, but the diagnosis should not be made until excluding other possiblities.
  • Anaphylaxis: This is a severe allergic reaction (often due to a bee sting, medications, or eating nuts or shellfish) that causes swelling in the throat and is a medical emergency.
  • Bronchitis: This can be both acute (lasting only a few days) or chronic (lasting weeks to months to years).
  • Bronchiolitis: This is an infection that involves the smallest airways (bronchioles) and is most common in children. It is often caused by the virus respiratory syncytial virus (RSV) that can lead to asthma far too often.
  • Inhaling (aspirating) a foreign body: Choking can sometimes cause wheezing if the object that is inhaled does not completely obstruct the airways. Often people recall choking, such as on a piece of steak or in the case of children, on other objects. But sometimes, especially when an object does not completely obstruct the airways (such as a piece of carrot), people may not remember a choking episode. On bronchoscopy studies in adults, 0.2% to 0.33% of the procedures discover a foreign body in a bronchial tube that was unexpected. Wheezing related to a foreign body is usually localized to one side of the chest.
  • Pneumonia
  • COPD: Chronic obstructive pulmonary diseases, such as emphysema, may cause wheezing.
  • Bronchiectasis: A widening of the airways often due to childhood infections or cystic fibrosis is sometimes difficult to diagnose and may at first be attributed to another cause of wheezing. While cystic fibrosis is most commonly diagnosed in early childhood, it is sometimes diagnosed in adulthood.
  • Viral infections such as a respiratory syncytial virus (RSV): Many viral infections can cause wheezing, especially in children.
  • Lung cancer: The first symptom of lung cancer may be wheezing, making it important to identify the cause of wheezing even if the cause appears obvious. With lung cancer, obstruction of the airway by the tumor leads to the wheezing sound.
  • Heart failure
  • Pulmonary embolism: Blood clots in the legs may break off and travel to the lungs (pulmonary emboli) can sometimes cause wheezing.
  • Acid reflux: It may not seem obvious, but acid reflux is a fairly common cause of wheezing. In some cases, people do not have symptoms such as heartburn and are unaware that they have acid reflux.
  • Hypersensitivity pneumonitis: Chronic inflammation of the lungs caused by such things as moldy hay and bird droppings may have wheezing as the first symptom.
  • Medications (especially aspirin)
  • Vocal cord dysfunction: Caused by one or both of the vocal cords closing unintentionally during breathing. This is also known as “vocal cord asthma.”
  • Epiglottitis: A medical emergency marked by symptoms such as fever, drooling, and sitting in an upright position in an attempt to breathe, epiglottitis is caused by an infection of the epiglottis, a small piece of cartilage attached to the end of the tongue. Epiglottitis often causes stridor that is heard over the neck but may also result in wheezing.


If you have been wheezing, it is important to see your healthcare provider—even if you feel you know the cause or have experienced wheezing in the past. Even if you have been diagnosed with asthma, make sure to contact your practitioner with any change in your symptoms.

Call your healthcare provider (or 911) immediately if you are experiencing chest pains, lightheadedness, are finding it hard to catch your breath or note a bluish tint to your lips and skin. Swelling of your face, neck, and lips could be a sign of a life-threatening allergic reaction.


The first thing your practitioner will do (after making sure you are comfortable and stable) is to take a thorough medical history and perform a physical exam. Some of the questions they may ask you include:

  • When did your symptoms begin?
  • Have you ever had symptoms like this before?
  • Is your wheezing worse at night or during the day?
  • Have you been stung by a bee or have you eaten foods that may cause serious allergic reactions, such as shellfish or nuts?
  • Do you have any other symptoms, such as a cough, shortness of breathchest painhives, swelling of your face or neck, or coughing up blood?
  • Do you have a personal or family history of asthma, eczema, lung diseases, or lung cancer?
  • Do you, or have you ever, smoked?
  • Have you choked while eating?


Tests to evaluate your wheezing and determine a cause will vary depending upon your history. In an emergency, emergency personnel and technicians begin with "ABD." This stands for airway, breathing, then circulation. It is important to assess these before going on to try to determine what is actually causing the wheezing. Testing may include:

  • Oximetry to check the oxygen level in your blood
  • Chest X-ray: It's important to note that a chest X-ray can be helpful if it finds something, but cannot exclude all serious conditions.
  • Spirometry
  • Blood tests, such as a white blood cell count to look for signs of infection
  • Pulmonary function tests
  • CT scan of your chest
  • Bronchoscopy if your healthcare provider is concerned that you may have aspirated (breathed in) a foreign object or that you may have a tumor in or near your airways
  • Laryngoscopy to look at your larynx and vocal cords
  • Allergy testing if your practitioner feels that you have allergies that are causing your airways to spasm


Depending on how serious your symptoms are, your healthcare provider will first do what is necessary to make you comfortable and control your symptoms. Since there are many possible causes of wheezing, further treatment will depend on the cause of your wheezing.

The first steps are to ensure you are getting adequate oxygen into your lungs and that the oxygen you breathe in makes it to all of the cells of your body. Oxygen therapy is commonly used. If an allergic reaction is the cause, injectable epinephrine is often given.

Other treatments will depend upon the underlying causes of the wheezing. For example, treatments for asthma will be used to alleviate narrowing of the airways due to asthma, whereas a procedure such as a bronchoscopy may be recommended if it's thought that a foreign body in the airways could be causing your symptoms.

A Word From Verywell

There are two extremely points to make, one worth reiterating, and one important to discuss.

There are many causes of wheezing. Even if a person has asthma, wheezing could potentially be a symptom of another, and possibly life-threatening condition. 

In addition, people still die from asthma, and far too often. Treatments have advanced significantly for asthma in the last decades, and many people are able to live relatively normal lives despite their disease. Yet the drugs that are prescribed to help people live "normal" lives are often very strong medications. Even though these drugs are used for people who are at home and work, outside of the hospital, they are still what healthcare providers refer to as "big guns." What this means is that there may be few options for emergency treatment once a person actually seeks medical care, with the exception of placing a tube (intubation and ventilation). And even intubation and ventilating the lungs, or as a last resort, extracorporeal membrane oxygenation (ECMO), can be very difficult once a person has status asthmaticus.

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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.
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  2. MedlinePlus. Wheezing. Updated May 20, 2018.

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  4. Ramos MB, Botana-Rial M, Garcia-Fontan E, Fernandez-Villar A, Torreira MG. Update in the extraction of airway foreign bodies in adultsJournal of Thoracic Disease. 2016;8(11):3452–3456. doi:10.21037/jtd.2016.11.32

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  6. American Academy of Allergy Asthma and Immunology. Asthma treatment and management.

  7. Alzeer AH, Al Otair HA, Khurshid SM, Badrawy SE, Bakir BM. A case of near fatal asthma: The role of ECMO as rescue therapyAnn Thorac Med. 2015;10(2):143–145. doi:10.4103/1817-1737.152461

Additional Reading
  • Harrison's Principles of Internal Medicine, 20th Edition. New York: McGraw Hill Education. 2019. Print.

  • Murray and Nadel's Textbook of Respiratory Medicine, 6th Edition. Elsevier. 2015.

  • Oo, S., and P. Le Souef. The wheezing child: an algorithm. Australian Family Physician. 2015. 44(6):360-4.