A bronchospasm is a contraction in the airways that can make it hard to catch your breath. Certain health conditions, such as asthma, and environmental triggers, like chemicals or cold air, can trigger it.

Bronchospasm is a tightening of the muscles that line the airways (bronchi) in your lungs. When these muscles tighten, your airways narrow. This can prevent air from entering or leaving your lungs.

Narrowed airways don’t let as much air come in or go out of your lungs. This limits the amount of oxygen that enters your blood and the amount of carbon dioxide that leaves your blood.

Bronchospasm often affects people with asthma and allergies. It contributes to asthma symptoms such as wheezing and shortness of breath.

When you have bronchospasm, your chest feels tight, and it can be hard to catch your breath. Other symptoms include:

  • wheezing (a whistling sound when you breathe)
  • chest pain or tightness
  • coughing
  • fatigue
  • dizziness

Any swelling or irritation in your airways can cause bronchospasm. This condition commonly affects people with asthma.

Other factors that can contribute to bronchospasm include:

To diagnose bronchospasm, you can see your primary care doctor or a pulmonologist (a doctor who treats lung diseases). The doctor will ask about your symptoms and find out if you have any history of asthma or allergies. Then, they’ll listen to your lungs as you breathe in and out.

You may have lung function tests to measure how well your lungs work. These tests may include the following:

  • Spirometry. In this test, you breathe into a tube that’s connected to a device called a spirometer. The spirometer measures the force of the air as you breathe in and out.
  • Lung volume test. This test measures how much oxygen your lungs can hold.
  • Lung diffusion capacity. In this test, you breathe in and out through a tube to see how well oxygen gets into your blood. Your doctor might also test your level of hemoglobin — a protein that helps transport oxygen in your blood.
  • Pulse oximetry. A device is clipped onto your finger to measure the oxygen level in your blood.
  • Eucapnic voluntary hyperventilation. This test is used to diagnose exercise-induced bronchospasm. You breathe in a mixture of oxygen and carbon dioxide to simulate breathing during exercise. Your doctor will see if breathing in this mixture affects your lung function.

You might also have one of these tests:

  • Chest X-ray. Your doctor will use a chest X-ray to look for pneumonia or other signs of infection.
  • CT scan. This test uses X-rays to look for problems in your lungs.

Your doctor may treat your bronchospasm with medications that widen your airways and help you breathe easier. These medications may include:

  • Short-acting bronchodilators. These medications are used for quick relief of bronchospasm symptoms. They start working to widen the airways within a few minutes, and their effects last for up to 4 hours.
  • Long-acting bronchodilators. These medications keep your airways open for up to 12 hours but take longer to start working.
  • Inhaled steroids. These drugs lower swelling in your airways. You can use them for long-term management of bronchospasm. They also take longer to start working than short-acting bronchodilators.
  • Oral or intravenous (IV) steroids. These may be required if your bronchospasm is severe.

If you get exercise-induced bronchospasm, take your short-acting medication about 15 minutes before you work out.

You might need to take antibiotics if you have a bacterial infection.

Here are a few things you can do to help prevent bronchospasm:

  • Warm up for 5–10 minutes before you exercise, and cool down for 5–10 minutes afterward.
  • If you have allergies, don’t exercise when the pollen count is high.
  • Drink lots of water throughout the day to loosen up any mucus in your chest.
  • Exercise indoors on very cold days. Or wear a scarf over your nose and mouth when you go outside.
  • If you smoke, ask your doctor for advice to help you quit. Try to avoid staying near people who smoke.
  • If you’re age 65 or older, or if you have a chronic lung condition or immune system problem, try to stay up to date on your pneumococcal and influenza vaccines.

Call your doctor if you have symptoms of bronchospasm that limit your daily activities or don’t clear up in a few days.

Also call if:

  • you have a fever of 100.4°F (38°C) or higher
  • you’re coughing up a lot of dark-colored mucus

Call 911 or go to an emergency room if you have these symptoms:

  • chest pain when you breathe
  • coughing up bloody mucus
  • trouble catching your breath