Kids with asthma might have days with no breathing problems at all. That's a relief for parents and kids both because it means that the asthma is under control.

But when asthma symptoms like wheezing, coughing, or shortness of breath become more severe, more frequent, or both, it's known as an asthma flare-up (also called an asthma flare, attack, episode, or exacerbation).

If the flare-up is severe, a person might:

• struggle to breathe or have rapid breathing even when sitting still
• be unable to speak more than a few words at a time without pausing
• have retractions (sucking in of muscles while inhaling) in the neck and chest

How a Flare-Up Affects Lungs

Here's what's happening inside the body when an asthma flare-up occurs. In the lungs, airways let air in and out. When someone has asthma, these airways, also called bronchial tubes and bronchioles, might be slightly inflamed or swollen even when the person is relatively well.

But during an asthma flare-up, the inflammation gets worse. Sticky mucus clogs these important tubes, and their walls get more swollen. The muscles around the airways get tight, further narrowing the airway (called bronchoconstriction). This leaves very little room inside for the air to flow through — think of a straw that's being pinched.

Causes of Asthma Flare-Ups

People with asthma have airways that are overly sensitive to certain things (called triggers) that normally don't bother those without asthma, and exposure to triggers can bring on asthma symptoms. Common triggers include:

• tobacco smoke
• cold air
• exercise
• infections, such as colds
• animal dander
• dust mites
• mold
• cockroaches

Many people with asthma also have allergies. In them, allergens — the things that cause the allergic symptoms — also can cause asthma flare-ups.

Left untreated, a flare-up can last for several hours or even several days. Rescue medications often take care of the symptoms pretty quickly. A person should feel better once the flare-up ends, although it can take several days to completely resolve.

Predicting Flare-Ups

The severity and duration of asthma flare-ups vary from person to person and even from attack to attack. They can happen without warning, with sudden coughing, shortness of breath, and wheezing. But because people with asthma have inflamed airways that worsen with gradual exposure to triggers, flare-ups also can build up over time, especially in those whose asthma isn't well controlled.

Flare-ups can and should be treated at their earliest stages, so it's important to know early warning signs that a child might experience just before a flare-up occurs. These clues are unique to each child and might be the same or different with each asthma flare-up.

Early warning signs include:

• coughing
• throat clearing
• rapid or irregular breathing
• unusual fatigue
• trouble performing everyday activities
• restless sleep or cough preventing sleep
• mild chest tightness or wheezing

A peak flow meter can help predict when a flare-up might be on its way, although not all flare-ups can be prevented. Because they can be life threatening, flare-ups demand attention. Your child might need to take rescue medication, visit the doctor, or even go to the hospital. Having a set of instructions (the asthma action plan) can help you know what action is needed.

Preventing Flare-Ups

To help prevent flare-ups:

• Make sure you or your child always carries an inhaler and spacer.
• Teach your child how to avoid asthma triggers.
• Make sure your child takes the controller medicine as the doctor directed — even if your child is feeling better, it's important not to skip it.
• Work with the doctor on an effective asthma action plan.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: August 2011
Originally reviewed by: Nicole Green, MD