• Sharebar

advertisement

 

Asthma

What Is Asthma?

Last updated on:
15/04/2013

Contributing Author: Guy Slowik FRCS

Asthma is a condition that affects the air passages of the lungs. It is a two-step problem:

  • When a person has asthma, the air passages are inflamed, which means that the airways are red and swollen.
  • Inflammation of the air passages makes them over extra-sensitive to a number of different things that can "trigger," or bring on, asthma symptoms.

During breathing, air is normally brought in through the nose where it is warmed, filtered, and humidified. It then passes through the throat and into the windpipe, called the trachea (TRAY-kee-a). The trachea divides into two large tubes called the right bronchus (BRONG-kus) and left bronchus. These then split up into much smaller tubes, which in turn branch into thousands of very small airways called bronchioles (BRONG-kee-olz). It is the large and small bronchi that are generally affected in asthma.

When a person is exposed to one of these irritants, or triggers, the oversensitive air passages react by becoming narrower, swollen, and even more inflamed. This obstructs airflow to and from the lungs and makes it very difficult for the person to breathe.

Nice To Know

Is All Asthma The Same?

Asthma is a chronic condition. This means that while it often looks like it goes away for awhile, the inflammation of the air passages remains present all the time. However, in some instances, this inflammation may go unnoticed for long periods of time. As long as the air passages are inflamed, asthma can flare up at any time. This is one of the reasons that an awareness of the triggers that cause the flare-ups is so important in preventing asthma episodes.

  • Allergic asthma - Allergic asthma is most common in children and adolescents. Usually, but not always, the allergies that cause the asthma appear before the age of 35. An asthma attack or episode occurs when a person comes into contact with something to which he or she has developed an allergy.
  • Nonallergic asthma - This type of asthma is most common in middle-aged adults. Asthma attacks may occur in response to triggers such as exercise, cold air, or respiratory infections. The allergic mechanism is not responsible for the asthmatic reaction.

What Is An Asthma Episode (Asthma Attack)?

Asthma symptoms can vary from very mild to very severe. Some adults with asthma have only seasonal bouts of symptoms. Some have symptoms only after exercise or after exposure to something to which they are allergic, such as a dog or cat. Others have a chronic form of the disease and experience asthma symptoms almost daily.

In an "asthma episode," also known as an "asthma attack," the symptoms develop because the oversensitive airways of the lung react by becoming more inflamed and narrows, thus obstructing the normal flow of air through the air passages. The reduced size of the air passages occurs because:

  • The muscles around the airways tighten
  • The linings of the airways become swollen
  • The normal secretion of the airways (called mucus) becomes "trapped," thus clogging the airways

As the airways become narrower and more obstructed, it takes extra effort to breathe and force air through them. The air may make a whistling or wheezing sound as it goes past the narrowed parts of the air passages. A person having an asthma attack may also cough a lot and spit up a lot of very sticky mucus.

So one or more of the following symptoms may occur once the airways have narrowed in response to a trigger:

  • Coughing. Coughing is often a sign of asthma, but is easily overlooked. As a general rule, healthy people don't cough unless they have something in their throats or have a cold.
  • Wheezing. Wheezing is a whistling noise heard during breathing, as if something is "caught" in one of the breathing passages.
  • Tightness of the chest. Many adults with asthma describe a tightness of the chest, an uncomfortable feeling caused by over-inflation of the lungs due to difficulty in pushing air out through the narrowed airways.
  • Shortness of breath. Shortness of breath is the feeling that a breath is barely finished before another is needed. It has been described as "air hunger" by some people.
  • Mucus production. Many people with asthma produce excessive, thick mucus that obstructs the airways, which can lead to coughing.

For many people, asthma symptoms are worse at night and in the early morning or after exercise. Furthermore, an asthma episode often gives early warning signs, thus giving the person time to act.

Nice To Know

Q. What makes my breathing passages so sensitive to triggers?

A. The underlying cause of the sensitivity in the airways is inflammation. Inflamed airways are highly reactive to triggers. In other words, they are easily irritated and respond by contracting, swelling, and filling with thick mucus. Some of the breathing passages don't have much supporting cartilage in their walls the way the windpipe does. As a result, they are not very "stiff" and are easily squeezed closed. Think of them as tiny tubes with thin muscle fibers wrapped around them like "rubber bands." If the "rubber bands" (airway muscle) tighten, the thin-walled passages are more easily choked off, making you short of breath.

Are Asthma Episodes Dangerous?

Most of the time asthma episodes are mild, and the airways will open up in a few minutes to a few hours in response to medication. But some attacks can be severe, lasting for a long time and not responding to the regular medication. And they can be very dangerous. A very severe, prolonged attack can threaten a person's life. Such an episode requires immediate emergency attention in a hospital.

Learning to recognize signals and take action to prevent asthma symptoms from becoming worse is an important step in the long-term control of asthma. So is managing an episode if it does occur.

Learning all about asthma will ultimately help a person have fewer and milder episodes and reduce the risk of a more serious attack. This includes understanding about:

  • The way your lungs work
  • The things that cause asthma episodes
  • The ways you can avoid those things
  • The medicines that help prevent and control symptoms

What Does "Good Asthma Control" Mean?

The long-term goal in asthma management is "good asthma control." In fact, because of a better understanding of the disease and the development of newer drugs, drug treatments are so effective that many adults with asthma can go for long periods of time without symptoms.

Good asthma control includes the following goals:

  • There is no wheezing, coughing, or shortness of breath.
  • Nighttime sleep is not interrupted by asthma symptoms.
  • Exercise and daily activities can be carried out normally.
  • Reliever medication is used less than three times per week.

For asthma treatment to be successful you need to learn all you can about asthma and its treatment, work closely with your doctor, and cooperate fully with other members of your health care team.

Facts About Asthma

  • The process of moving air into and out of the lungs is something most people take for granted. But for as many as 15 million Americans living with asthma, this simple activity requires significant effort.
  • Asthma cannot be cured, but with proper treatment it can be effectively controlled. Good asthma control allows most adults to live full, active, trouble-free lives.
  • Without satisfactory control of asthma, long-term damage can occur in the respiratory system. Poorly controlled asthma can lead to reduced physical activities, missed work, and extra visits to the emergency department.
  • For most adults with asthma, a reduced quality of life doesn't have to happen. Arming yourself with information is an important step in maintaining a healthy life.

 

 
 

advertisement

 

advertisement

Take Our Quiz

Stroke is a global disease that knows no boundaries. But few people know how to prevent stroke, or how to recognize signs and symptoms of stroke, or what to do when you suspect someone is having a stroke. What about you? How much do you know about stroke? Take this short quiz to test your stroke IQ.

take the quiz>>

Rate This Article

Your rating: None Average: 4.2 (5 votes)
 

From Andrew Maynard - Chair of the University of Michigan Department of Environmental Health Sciences, with help from David Faulkner - 2013 Master of Public Health graduate.