Asthma and Reactive Airway Disease (RAD) are conditions in which the airways (bronchi) in the lungs overreact to certain things. Understanding what the lungs look like and how they work will help you understand asthma or RAD episodes and how to control them. A diagnosis of asthma is made by your doctor based on family history, the number of RAD events and other factors.
The airways of the lungs are formed like an upside-down tree (Picture 1). It is much like the way the trunk of a tree divides into smaller branches and ends in leaves. The windpipe (trachea – TRAY-key-uh) is like the trunk of the tree. The trachea then branches off into smaller airways (bronchi - BRON-key) and ends in the air sacs (alveoli - Al-VEE-oh-li). Oxygen that is breathed in is carried from the bronchi to the alveoli where it can be used by the body.
Muscles (bronchial smooth muscles) surround the bronchi the way bark covers the outside of a tree. Inside the airways is a mucous membrane that covers the inside of the lungs like the lining of a coat. This membrane produces mucus (phlegm - Flem) that helps keep the lungs clean.
During an asthma or RAD episode, three things happen:
These changes make the airways narrow, so breathing is more difficult.
An episode occurs when a "trigger" (something that sets off an asthma or RAD episode) causes the airways to overreact and become very narrow. Most people who have asthma or RAD have more than one trigger. These vary from child to child. Being in contact with more than one trigger for a short time may cause an episode. For example, your child may be able to play in leaves and have no problems. But if he or she then plays with the family dog, the two together may cause breathing problems. Being around a strong trigger for awhile may also cause an episode. For example, your child may be able to pet a cat for a short time and have no trouble. However, he may have severe problems if the cat is kept in the house all the time.
Once you know what your child's triggers are, it’s important to keep him away from those that lead to an asthma or RAD episode (Picture 2).
The most common triggers are allergies and infections from viruses (like colds) and other germs.
Other triggers include:
It is much easier to stop an episode in its early stages. This is because more mucus is produced as the episode continues. Bronchospasms increase and more swelling occurs. Most people have early signs that let them know an episode is starting. Paying attention to these early warning signs can help stop the episode soon after it starts. Each person has different signs. You need to learn which ones happen to your child.
Many children have one or more of these signs that may signal an asthma episode.
Abnormal breathing where there is a deep "sucking in" when your child takes in a breath, making it easy to see the outline of his ribs. This is called retractions. In some cases you may not hear wheezing, yet other symptoms are present:
Sometimes you might also see:
Some children with asthma or RAD need to take medicine regularly to prevent breathing problems. There are many different medicines. Some important points about medicines are:
Children with asthma, RAD or wheezing should receive a flu shot once a year. Nasal influenza vaccine is not recommended. Talk to your child’s doctor for more information.
Most of the time, your child is not "sick." Avoid treating him as a "sick" child. The child with asthma or RAD does need to be careful about some things, but many of the things that cause breathing problems can be controlled. As your child gets older, he should take more responsibility for controlling his asthma or RAD. Talk with your doctor or nurse about ways to encourage this.
If you have any questions, be sure to ask your doctor or nurse.
HH-I-11 9/78, revised 6/11 Copyright 1978-2011, Nationwide Children's Hospital