Shortness of Breath

Reviewed by: HU Medical Review Board | Last reviewed: March 2024 | Last updated: March 2024

It can be scary to feel unable to get enough air when you breathe. Shortness of breath, also called dyspnea, breathlessness, or air hunger, can happen for many reasons. Whatever the cause, it may indicate a problem that needs attention.1-3

What is shortness of breath?

A series of physical reactions lead to breathlessness. Normally, your blood contains the right balance of oxygen and carbon dioxide. Your heart, lungs, and brain take care of keeping this balance. But if your heart, lungs, or airways are not working well, your oxygen level can drop. These events can all trigger your brain to make you breathe harder.1,3,4

Shortness of breath may feel like:1-5

  • You cannot get enough air when you breathe.
  • Your chest is tight.
  • You must work extra hard to take a deep breath.
  • You breathe fast or have a fast heart rate.
  • You make a whistling noise (wheeze) when you breathe.
  • You cannot tolerate pollen, pollutants, and allergens.

What causes shortness of breath?

Shortness of breath can be a symptom of many serious conditions, including:2,6

  • Heart conditions, such as heart failure, rhythm problems, or inflammation
  • Lung conditions, such as lung obstruction, infection, or blood clot
  • Asthma
  • Allergies
  • Heavy exercise or lack of exercise
  • Being overweight
  • Anxiety
  • Anemia

Certain indoor and outdoor conditions also can worsen shortness of breath. These conditions include:1,3,6

  • Smoke (from smoking yourself or secondhand smoke)
  • Dampness and mold
  • Poor air quality (allergens, pollen, pollutants, ozone)
  • High altitude

Why does shortness of breath happen with asthma?

Sometimes, shortness of breath happens suddenly, as with exercise, anxiety, allergies, or illness. Other times it is ongoing, such as with heart failure, lung disease, or asthma.2,4

With asthma, breathlessness flags a possible attack and is critical to monitor. Though it may come and go, shortness of breath is a sign that your airways are challenged. They may be swollen inside, clogged with mucus, or squeezed by tightening muscles. An episode can be mild, moderate, or severe. And it can happen during the day as well as at night.1-6

Studies show that shortness of breath is a serious asthma symptom. A 2020 study of more than 55,000 people with asthma reported that half the participants had shortness of breath. Nearly half also had a group of other symptoms at the same time. These symptoms included wheezing, chest tightness, trouble sleeping, and stuffy nose.1

Yet people with asthma-related shortness of breath often have no action plan for handling an attack. In a 2021 study of 7,955 adults, nearly 4 in 10 people with current wheezing had symptoms of severe asthma. But only 38 percent of them had developed a symptom management plan.6

How is shortness of breath diagnosed?

If you have any of the above symptoms, an allergy doctor (allergist) or lung doctor (pulmonologist) can help. First, they may ask the following questions about your condition:2

  • What does your shortness of breath feel like?
  • Is it a minor or major problem for you?
  • Do you wake up at night due to shortness of breath?
  • What else do you feel?
  • Do you feel this way every day, week, month?
  • How long has it been going on?
  • What are your home and working conditions like?

They also may test your lungs and breathing ability to find the cause of your breathlessness. Tests may include:2-4

  • Pictures of your chest and lungs (X-rays)
  • Blood oxygen level tests (pulse oximetry)
  • Exercise tests (stress tests)
  • Breathing tests (spirometry)

How is shortness of breath treated?

Your doctor will suggest ways to manage your shortness of breath. These methods may include:1-3,5

Your doctor also can teach you to identify signs of an upcoming episode. They might have you use a peak flow meter to monitor air passing through your lungs. This will warn you of lessened airflow even before you feel short of breath. You can then take steps to stop an attack.3

Finally, you and your doctor can create a written plan to handle breathlessness. The Asthma and Allergy Foundation of America (AAFA) recommends including green, yellow, and red levels in your plan:2,3

  • Green – Steps for staying symptom-free, like taking prescribed preventive drugs, especially before exercise
  • Yellow – Steps for stopping sudden shortness of breath, cough, chest tightness, wheezing, and night awakening. This may require inhaling a quick-acting drug and contacting your doctor.
  • Red – Steps for handling an emergency, when your symptoms continue despite treatment. You need to seek medical help quickly.

The bottom line

If you have trouble breathing, talk to your doctor. If your symptoms trouble you, do not ignore them. Your doctor will assess the problem and help you understand the cause. If the cause is asthma, your doctor will help you create a plan to manage and treat it. With awareness and a plan, you can improve your quality of life despite shortness of breath.1-6

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