To print: Use your web browser's print feature. Close this window after printing.

Asthma Attack

Table of Contents


When asthma symptoms suddenly occur, it's called an asthma attack. It's also called an acute asthma episode, flare-up, or exacerbation. Attacks can be brief (about an hour) or last for several days. They may be seasonal (similar to hay fever) or occur during any season.

What are the symptoms?

When you have an asthma attack, airflow to the lungs is reduced.

During an asthma attack:

Asthma symptoms may start suddenly or happen up to several hours after you have been exposed to triggers, such as tobacco smoke or animal dander. In some cases, symptoms may not occur until 4 to 12 hours after contact. Although severe attacks may seem to occur suddenly, they usually occur after several days of increasing symptoms.

What causes it?

Asthma attacks are caused by:

Anything that makes your asthma or breathing worse can cause an asthma attack.

It may be things that you are allergic to, such as:

Other things can cause an asthma attack too, such as:

How is it treated?

An asthma action plan is a written plan that tells you what asthma medicine to take every day and how to treat an asthma attack. It can help you make quick decisions in case you are not able to think clearly during an attack.

How can you prevent an attack?

There's no certain way to prevent asthma. But you can reduce your risk of asthma attacks by avoiding things that cause them.

The goal is to reduce how many asthma attacks you have, how long they last, and how bad they get.

Here are some ways to help avoid asthma attacks.

Credits for Asthma Attack

Current as of: August 6, 2023

Author: Healthwise Staff (
Clinical Review Board (
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Note: The "printer friendly" document will not contain all the information available in the online document. Some information (e.g. cross-references to other topics, definitions or medical illustrations) is only available in the online version.

© 1995-2023 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.