What Is Asthma?

Asthma Definition

Asthma is a chronic lung disease that causes episodes of difficult breathing. This is primarily due to constriction, tightening of the muscles surrounding the airways, and inflammation, soreness, swelling and irritation of the airways in the lungs.

Asthma 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

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:

• Allergic asthma
• Exercise induced asthma
• Occupational asthma
• Cough variant asthma
• Nocturnal (nighttime) 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 asthmatic, this process is different and more difficult. In asthma, the airways of the lung are made smaller or narrowed by both constriction and inflammation. Constriction and inflammation causes an airflow obstruction that makes it difficult to breathe.

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.

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 classical symptoms of asthma:

• Wheezing
• Chest tightness
• Shortness of breath
• Chronic cough

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:

• Pulmonary function testing
• Chest x-ray
• Blood tests

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.

Prevention

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.

_Sources:

_{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}