Medical News Today: What is a bronchospasm and what causes it?

A bronchospasm occurs when the muscles that line the airways of the lungs constrict or tighten, reducing airflow by 15 percent or more.

People with asthma, allergies, and lung conditions are more likely to develop bronchospasms than those without these conditions, as are young children and people over 65 years of age.

Bronchospasms, in themselves, are not considered contagious, but some of the viruses and bacteria that cause bronchospasms can be transmitted to other people.

What causes bronchospasms?

3D model of lungs and airways.
Bronchospasms may be caused by respiratory conditions, such as asthma or bronchitis, as well as medication or irritants.

Some medical conditions, allergens, and medications can cause bronchospasms.

Common causes of bronchospasms include:

  • asthma
  • chronic obstructive pulmonary disorder (COPD)
  • emphysema
  • chronic bronchitis
  • viral, bacteria, and fungal lung infections
  • smoking
  • air pollution or smoke
  • environmental allergens, such as pet dander, pollen, mold, and dust
  • some food additives and chemicals
  • fumes from chemicals used in cleaning products and manufacturing
  • cold weather
  • general anesthesia, mostly causing airway irritation
  • exercise
  • blood-thinning medications, such as blood pressure medications and non-steroidal anti-inflammatories (NSAIDs)
  • antibiotics

Scientists are still not sure why but, in some people, exercise appears to induce bronchospasms. Traditionally, bronchospasms brought on by exercise were considered a symptom of asthma, but new studies have revealed this may not be true.

A 2014 study surveying almost 8,000 French schoolchildren concluded that exercise-induced bronchospasms seem to be a separate, independent condition from asthma.

The same study found that bronchospasms were associated with several types of atopic rhinitis, a chronic condition causing dry crusts to form in the nasal cavities and the gradual loss of the mucosal lining.

Researchers are also still trying to determine whether newer smoking alternatives, such as electronic cigarettes, cause bronchospasms. Nicotine has been shown to stimulate the primary nerve of the lungs, triggering muscle constriction and bronchospasms.

A 2017 study found that a single puff from an e-cigarette containing 12 mg/ml of nicotine was enough to cause bronchospasms in anesthetized guinea pigs.

Some chemicals found in medications used to open the airways (bronchodilators) have also been shown to cause bronchospasms, though this is rare.

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Woman coughing into hand.
Potential symptoms of bronchospasm include coughing, breathing difficulty, and pain in the chest.

The signs of bronchospasm are fairly apparent while the severity of symptoms is directly related to how much the airways have narrowed, or how much airflow has been restricted.

Common symptoms of bronchospasm include:

  • pain, tightness, and a feeling of constriction in the chest and back
  • difficulty getting enough air or breathing
  • a wheezing or whistling sound when inhaling
  • coughing
  • feeling tired or exhausted for no apparent reason
  • feeling light-headed or dizzy


A doctor will need to diagnose and prescribe treatment for bronchospasms. For complicated or severe cases, a pulmonologist or doctor who specializes in the lungs may help confirm the diagnosis.

Typically, a doctor will ask questions about a person’s history of lung conditions and allergies, before listening to the lungs with a stethoscope.

Depending on the severity of the symptoms, and if bronchospasms are suspected, the doctor may perform a series of tests to assess how constricted or reduced the person’s airflow and breathing are.

Common tests used to help diagnosis bronchospasms include:

  • Spirometry, lung diffusion, and lung volume tests: The individual breathes in and out several times with moderate and maximum force through a tube connected to a computer.
  • Pulse oximetry tests: A device that measures the amount of oxygen in the blood is attached to the finger or ear.
  • Arterial blood gas tests: A blood test is done to determine the levels of oxygen and carbon present.
  • Chest X-ray and computed tomography (CT) scans: Images of the chest and lungs can be taken to rule out infection or lung conditions.

To determine whether bronchospasm is caused by exercise, a doctor may recommend a eucapnic voluntary hyperventilation test. During this test, an individual inhales a mix of oxygen and carbon dioxide to see how it changes their lung function.

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When should people see a doctor?

A person should seek immediate medical attention whenever they experience severe, ongoing, or distressing bronchospasms. If airflow is extremely compromised, they should call 911 or go to the emergency department.

Additional reasons to speak with a doctor include:

  • very painful bronchospasms
  • spasms that interfere with everyday activities
  • spasms that cause dizziness or light-headedness
  • spasms that occur after inhaling an allergen
  • spasms that occur for no apparent reason
  • spasms that get worse or only occur during exercise
  • coughing up mucus, especially if dark or discolored
  • fever and a temperature of more than 100 °F
  • significant difficulty getting enough air or breathing

What are the most effective treatments?

Bronchodilators in the form on inhalers.
Bronchodilators are available in different forms, though they may provide the most relief when inhaled.

In most cases of bronchospasm, a doctor will prescribe bronchodilators. These drugs cause the airways to widen, increasing airflow.

The three most common types of bronchodilators are beta-agonists, anticholinergics, and theophylline.

Though the medications used to treat bronchospasms come in tablet, injectable, and liquid forms, many are considered to be most effective when inhaled.

The best treatment plan depends on individual factors, such as the severity of the spasms, how often they occur, and their cause.

For severe or chronic cases, doctors may recommend steroids to reduce inflammation in the airways and increase airflow. When bronchospasms are caused by bacterial infections, doctors may also prescribe antibiotic medications.

Common medications used to treat bronchospasms include:

Short-acting bronchodilators

This type of bronchodilator starts working within minutes, and its effects last for several hours.

Doctors prescribe short-acting bronchodilators for quick relief from sudden, severe spasms and for treating exercise-induced spasms. Typically, an individual should only take these drugs once or twice a week.

Most short-acting bronchodilators are available in a liquid form that becomes an inhalable mist after being passed through a device called a nebulizer.

Common short-acting bronchodilators include:

  • AccuNeb, Proair, Ventolin
  • Metaproterenol
  • Xopenex
  • Maxair

Long-acting bronchodilators in combination with steroids

For chronic cases of bronchospasm, long-acting medications may be prescribed in combination with inhaled steroids to help prevent spasms.

In most cases, people take long-acting bronchodilators two or three times per day and at scheduled times. These drugs are not helpful for quick relief of spasm symptoms.

Common long-acting bronchodilators and inhaled corticosteroid medications include:

  • Advair
  • Symbicort
  • Serevent
  • Foradil
  • Flovent
  • Prednisolone
  • Pulmicort

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If a person’s bronchospasms are exercise-induced, taking long-acting bronchodilators and inhaled corticosteroid medications 15 to 20 minutes before exercise can help reduce the chances of having spasms.

If exposure to an allergen, irritant, or medicine, causes a bronchospasm, avoiding or stopping exposure to it will also help reduce or prevent spams.

For bronchospasms caused by general anesthesia, doctors usually prescribe additional anesthesia medicine. If this does not resolve the spasms, short-acting bronchodilators and intravenous corticosteroids may be used.

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