What Causes Wheezing?

What does it mean if I hear wheezing?

Patient consulting Doctor for breathing difficulties, Asthma
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What causes wheezing? The cause is not always simple or straightforward and may be difficult for your doctor to figure out.

You may monitor your child for it and talk to your doctor about it, but do you know what wheezing really is and what generates the noise you hear?

Wheezing is both common and scary. It is one of the main reasons patients and parents go to the doctor or emergency department.

Learn a little more about what causes wheezing and what you might need to do about it.

What Is Wheezing?

Wheezing is one of the classical symptoms of asthma. Others include:

Wheezing can be defined as the high-pitched, whistle-like sound that you hear when breathing through your mouth or nose. Wheezing is most commonly heard when you are breathing out, but can also be heard when breathing in. The musical sound results from air moving through narrowed airways. If you have not heard wheezing, it sounds like this.

What Causes Wheezing?

Wheezing results when your airways narrow; as a result, air is more turbulent and has difficulty moving through your lungs. The obstruction leads to a whistling noise as air is forced through your lungs.

Not All That Wheezes Is Asthma

While asthma is the most common cause of chronic or recurrent wheezing, wheezing is not always asthma. "Not all that wheezes is asthma!" is a mantra that is heard in medical school all the time. A number of different medical problems can lead to wheezing. Some are serious, and some are not. However, wheezing should never be ignored, and it would never be considered normal. Here are just a few of the other conditions that might lead to wheezing.

  • Anaphylaxis: This is a severe allergic reaction that can lead to the sudden onset of wheezing. It is a medical emergency that is potentially life-threatening.
  • Bronchitis: This term is often used as a generic term for inflammation of the airways. Some physicians refer to recurrent episodes of wheezing and coughing as bronchitis.
  • Bronchiolitis: In the wintertime, this cause of wheezing is commonly due to the respiratory syncytial virus, but other viruses can also cause wheezing, such as adenovirus, influenza, or parainfluenza. The virus is a risk factor for developing recurrent wheezing and asthma symptoms.
  • Cystic fibrosis: People with this condition often experience poor growth in childhood, weight problems, cough, and shortness of breath in addition to wheezing. The wheezing is usually part of underlying respiratory problems (e.g., bronchiectasis and pneumonia), as opposed to an inflammatory asthma-like condition.
  • Congestive heart failure (CHF): Here the wheezing is due to fluid build-up in the lungs, leading to decrease airflow as opposed to inflammation. Unlike wheezing in asthma patients, CHF patients will often have a large heart on chest x-ray, and a heart ultrasound will demonstrate poor performance or a decreased ejection fraction. In this condition, the heart no longer adequately pumps blood to the body.
  • COPD: The wheezing sound is due to narrowed airways like in asthma, but the pathophysiology of COPD differs from that of asthma.
  • Foreign body: Think peanut or Mardi gras bead. Unlike asthma, the wheezing is often localized to one place.
  • GERD: Bronchospasm can result from aspirating acid into the lungs, or the airways can narrow as a result of acid going into the esophagus.
  • Lung cancer: Similar to a foreign body, lung cancer may cause localized wheezing.
  • Vocal chord dysfunction: In this condition, also called paradoxical vocal fold motion, the vocal cords close rather than open on inhalation. You may experience wheezing, but do not benefit from asthma treatment.
  • Pulmonary embolism: This is a blood clot in the lungs. Wheezing may be one of several symptoms, but patients more commonly have acute shortness of breath and chest pain.

What Should I Do If I Hear Wheezing?

You should see a doctor soon if:

  • You have not wheezed previously.
  • You’ve wheezed before, but it is getting worse.

Any of the following symptoms should cause you to seek emergency care right away:

  • Wheezing while breathing both in and out
  • Continuous coughing
  • Difficulty breathing
  • Tachypnea, or breathing very fast
  • Retractions, in which your skin is pulled in as you breath
  • Shortness of breath
  • Difficulty talking in complete sentences
  • Becoming pale
  • Becoming anxious
  • Blue lips or fingernails (called cyanosis)

Wheezing is never normal, so it is important to seek care if you are concerned. Only your doctor or health care provider will be able to determine if your wheezing is from asthma or some other condition.

Learn More About What Causes Wheezing

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Article Sources
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  1. Patel PH, Mirabile VS, Sharma S. Wheezing. StatPearls. Updated September 16, 2019.

  2. MedlinePlus. Wheezing. Updated May 5, 2018.

  3. Cleveland Clinic. Asthma symptoms. Updated May 10, 2017.

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