1. Health
Send to a Friend via Email
You can opt-out at any time. Please refer to our privacy policy for contact information.

What Is Asthma?

Definition, Statistics, Types & Causes of Asthma


Updated August 01, 2010

What Is Asthma

What Is Asthma

Photo © Stockbyte

What Is Asthma- A Definition

What is asthma is a common question among newly diagnosed asthma patients. Asthma is a chronic lung disease that causes episodes of difficult breathing. Asthma symptoms are caused primarily due to constriction, tightening of the muscles surrounding the airways, and inflammation, soreness, swelling and irritation of the airways in the lungs.

What Is Asthma- Important Statistics

More than 22 million people -- and some 6 million children -- have asthma. Everyday in the United States:

  • 40,000 people will miss school or work because of asthma
  • 30,000 people will have an asthma attack
  • 5,000 people will visit the emergency room because of their asthma
  • 1,000 people will be admitted to the hospital because of asthma
  • 11 people will die due to asthma

What Is Asthma- Different Types of Asthma

There are actually several different types of asthma. Understanding the specific type of asthma you have can help you get the most effective treatment. Some the types of are:

What Is Asthma- Causes of Asthma

Asthma has increased dramatically over the last several decades. While the exact cause of asthma is unknown, many think the following factors act together to cause asthma or are risk factors for asthma:
  • Atopy, or an inherited tendency to develop allergy
  • Family history of asthma
  • Contracting certain respiratory infections in early childhood
  • Exposure to some airborne allergens and viral infections during early childhood as the immune system develops.
  • Other allergens like animal dander
  • Allergic rhinitis
  • Exposure to cigarette smoke
  • Obesity
  • Airway hyperreactivity (an exaggerated airway responsiveness to various stimuli)

Normal vs. Asthmatic Breathing

When a person without asthma breathes in, the air:

  1. Enters through the nose or mouth.
  2. Goes down the trachea, or windpipe.
  3. Enters the bronchioles, or airways of the lung.
  4. Blood is oxygenated at the alveoli.
  5. Goes back out again.

However, for asthmatics, this process is different and more difficult. In asthma patients, the airways are very sensitive and may react to a number of different triggers, such as smoke, pollens and infections, leading to constriction and inflammation of the airways.Constriction and inflammation cause airflow obstruction, making it difficult to breathe.

Asthma symptoms will wax and wane over time with treatment focused on both the prevention and control of symptoms and the reduction of inflammation.

Asthma Symptoms

The constriction and inflammation may cause patients to experience some or all of the following symptoms:

Everyone's asthma is different. You may experience other symptoms and symptoms will vary in intensity. For more information about signs and symptoms of asthma, visit About.com's Symptom Checker, an interactive tool to help you learn more about signs and symptoms of asthma and other diseases.

Diagnosing Asthma

In general diagnosing asthma requires 2 specific criteria:

  1. Presence of symptoms compatible with asthma.
  2. Objective measurement of decreased airflow in your lungs using a specific measurement like peak expiratory flow.

Your health care provider will generally take a detailed history from you and perform a physical exam. Your healthcare provider may order tests to assist in making a diagnosis such as:

Asthma Treatment

Treatment for your or your child's asthma will primarily involve three main components:

  1. Monitoring of your peak expiratory flow and asthma symptoms.
  2. Avoidance of triggers.
  3. Treatment with medications.

It is important that you regularly visit your healthcare provider and follow your action plan inorder to get control of your asthma.


While medicine cannot currently prevent you or your child from getting asthma, you can learn how to get control of asthma and prevent asthma symptoms from significantly impacting you.

What Is Asthma- Learn More About Asthma Prevention

What Is Asthma- Frequently Asked Questions

Patients often ask a number of different questions related to asthma. Maybe these will help you. If not ask your own question and see it get answered.


American Academy of Allergy Asthma & Immunology. Consumer Information Sheet. Accessed: January 1, 2008. Asthma Statistics

National Heart, Lung, and Blood Institute. Accessed: January 1, 2008. Expert Panel Report 3 (EPR3): Guidelines for the Diagnosis and Management of Asthma

  1. About.com
  2. Health
  3. Asthma
  4. Asthma Basics
  5. What Is Asthma- All About What Is Asthma

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.