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Asthma attack

Medically reviewed by Last updated on Oct 5, 2023.


An asthma attack is a sudden worsening of asthma symptoms. Asthma is a long-term condition that makes breathing difficult because airways in the lungs become narrow. Symptoms of asthma attack include coughing, wheezing, tightness in the chest and difficulty getting enough air.

These symptoms happen because muscles around airways tighten up, the airways become irritated and swollen, and the lining of the airways produces a fluid called mucus. All of these factors make it difficult to breathe.

People who already have a diagnosis of asthma usually have an asthma action plan. This tells them what medicines to take if they have an asthma attack and when to get emergency care. People who do not have a diagnosis or don't have a treatment plan should get emergency care if they have these symptoms.

Frequent asthma attacks show that a person's asthma is not under control. A healthcare professional might make changes in medicines and the asthma action plan to improve control.

An asthma attack also is called an asthma exacerbation or asthma flare-up.


Symptoms of asthma attacks may include:

Severe symptoms also may include:

The result of an at-home test, called a peak flow meter, can be an important sign of an asthma attack. This device measures how quickly you can force air out of your lungs. Peak flow readings are usually a percentage of how your lungs work at their best. This is called your personal best peak flow.

An asthma action plan often includes steps to take based on a peak flow reading. A reading below 80% of a best peak flow can be a sign of an asthma attack.

When to see a doctor

An asthma action plan tells you when to call your healthcare professional and when to get emergency care. A plan has three parts with color codes:

If you do not have an asthma action plan, get emergency care if quick-relief medicine is not helping symptoms.

Checkups for asthma control

It's important to keep regular appointments with your healthcare professional. If your asthma is under control, you may be able to take lower doses of medicine. If you are using a rescue inhaler too often to treat asthma attacks, you may need changes to your asthma action plan. These might include taking a new medicine or higher doses of a medicine.


Asthma is usually a lifelong disease of inflammation in the lungs caused by an overactive immune system. Inflammation in the lungs includes the tightening of muscles around airways, swelling of tissues in the airways and the release of mucus that can block airways. When this happens, it's difficult to breathe.

Asthma attacks occur when something triggers the immune system to take action. Triggers may include:

Risk factors

Anyone who has asthma is at risk of an asthma attack. Factors that can increase the risk include:


Asthma attacks affect both a person's health and quality of life. Problems may include:

Severe asthma attacks can cause death. Life-threatening asthma attacks are more likely for people who frequently use quick-relief medicines, have had emergency room visits or hospital stays to treat asthma, or have other long-term illnesses.


An important step to prevent an allergy attack is to follow your asthma action plan:

Your input on how well the plan is working helps your healthcare professional adjust the treatment to prevent asthma attacks.

Other steps to prevent asthma attacks include the following:


If your symptoms don't improve with at-home treatment, you will need to see your healthcare professional or get emergency care. Even if symptoms improve with at-home treatment, your healthcare professional may want to see you soon for an exam, depending on the severity of symptoms.

If you go to your clinic or the emergency room for treatment, you will likely get treatments and have tests at the same time. The goal is to improve your breathing, to judge how severe an asthma attack is and to see whether the treatment is working.

Tests to measure how well your lungs are working may include:


The goal of management is to treat an asthma attack at home by following your asthma action plan. At-home treatment may be enough to improve symptoms and make breathing easier.

The instructions in the plan also tell you when to see your healthcare professional or get emergency care.

Yellow zone

The yellow zone of an asthma action plan is having moderate asthma symptoms and a peak flow reading of 50% to 79% of your personal best. If you're in the yellow zone, the plan will tell you how many puffs of your quick-relief medicine to take and how often you can repeat the dose. Young children or people who have difficulty with an inhaler use a device called a nebulizer to inhale the medicine in a mist.

Quick-relief medicines include:

The yellow zone of the plan also will tell you:

Your healthcare professional may tell you whether to take additional doses or change doses of a medicine. You'll likely get instructions about monitoring your symptoms. You may be instructed to go to the clinic or emergency room.

Red zone

The red zone in an asthma action tells you to get emergency care if:

Emergency treatment

If you go to the emergency room for an asthma attack in progress, you'll likely get a number of treatments to restore regular breathing. Treatments may include:

You will be in the emergency room or in the hospital for observation or treatment until you are breathing regularly for some time.

You'll be given instructions for:

Preparing for an appointment

If you are getting emergency care, bring your asthma action plan and medicine with you if possible. If you are seeing your primary healthcare professional for treatment or a follow-up appointment, you can prepare by doing the following:

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. Some good questions to ask your doctor include:

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.

What to expect from your doctor

Your healthcare professional will likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

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