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Definition

Asthma is inflammation and narrowing of the bronchial tubes. Air travels in and out of the lungs through these tubes.

Inflamed Bronchus in the Lungs

2009 Nucleus Medical Art, Inc.

Causes

The cause of asthma is not known. It does seem to run in some families. Current research suggests a combination of environment, genetics and biology may lead to asthma. Possible triggers of an asthma attack in a person with asthma include:

  • Exercise
  • Cold weather
  • Viral illness
  • Sinusitis]]>
  • ]]>Gastroesophageal reflux disease]]> (GERD)
  • Sulfites used in dried fruits and wine
  • Medications, such as ]]>aspirin]]> , ]]>ibuprofen]]> , and beta-blockers
  • Exposure to irritants or allergens, including:
    • Cigarette smoke, smoke from a wood-burning stove
    • Pet dander
    • Dust
    • Chemicals
    • Mold and mildew
    • Pollen
    • Smog or air pollution
    • Perfumed products

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Risk Factors

These factors increase your chance of developing asthma. Tell your doctor if you have any of these risk factors:

  • Living in a large urban area
  • Regularly breathing in cigarette smoke]]> (including second-hand smoke)
  • Regularly breathing in industrial or agricultural chemicals
  • A parent who has asthma
  • History of multiple respiratory infections during childhood
  • Low birth weight
  • Being overweight
  • ]]>Gastroesophageal reflux disease]]> (GERD)

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Symptoms

Symptoms include:

  • Wheezing
  • Tightness in the chest
  • Trouble breathing
  • Shortness of breath
  • Cough]]>
  • Chest pain
  • Self-limited exercise, difficulty keeping up with peers

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Diagnosis

The doctor will ask about your symptoms and medical history and perform a physical exam:

Tests may include:

  • Peak flow examination—blowing quickly and forcefully into a special instrument that measures your output of air
  • Pulmonary function tests]]> (PFTs)—breathing into a machine that records information about the function of your lungs
  • Bronchoprovocation tests—lung function tests performed after exposure to methacholine, histamine, or cold or dry air to stimulate asthma; can help to confirm asthma in unclear cases
  • Exhaled nitric oxide (a marker of airway inflammation)—to suggest the diagnosis and manage medications
  • ]]>Allergy tests]]> —usually skin or sometimes blood tests to find out if allergies may be contributing to the symptoms

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Treatment

The treatment approach to asthma is four-fold:

  • Regular assessment and monitoring
  • Control of contributing factors (eg, gastroesophageal reflux and sinusitis]]> ), avoidance of allergens or irritants
  • Patient education ]]>*³]]>
  • Medications

Often, you'll need to take more than one type of medication.

Asthma Medications

Medications Used to Control Asthma

These medications are used to control the condition and avoid asthma attacks, not to treat an acute attack:

  • Inhaled corticosteroid—used daily to reduce inflammation in your airways
  • Long-acting beta agonists—(eg, inhaled ]]>salmeterol]]> ) used daily to prevent asthma attacks; should not be taken without an inhaled corticosteroid
    • May increase the risk of asthma-related death, intubation (putting a tube in the windpipe to breath), and hospitalization—If you have any concerns, talk to your doctor. ]]>*²]]>
  • ]]>Cromolyn sodium]]> or nedocromil sodium inhaler—used daily to prevent asthma flare-ups or to prevent exercise-induced symptoms
  • ]]>Zafirlukast]]> , ]]>zileuton]]> , and ]]>montelukast]]> —taken daily to help prevent asthma attacks
  • ]]>Omalizumab]]> (Xolair)—a monoclonal antibody against immunoglobulin E (IgE), given as an injection under the skin, used along with other medications
  • ]]>Theophylline]]> —taken daily to help prevent asthma attacks, not as commonly used because of interactions with other drugs

Medications Used to Treat an Asthma Attack

These medications are used to treat an asthma attack:

  • Quick-acting beta agonists—(eg, inhaled ]]>albuterol]]> , ]]>xopenex]]> ) relax your airways so that they become wider again, may also be used to avoid exercise-induced asthma attacks
  • Anticholinergic agents—inhaled medications, such as ]]>ipratropium]]> , that function as a bronchodilator, typically only used in an emergency setting
  • Corticosteroids—pills, injections, or intravenous (IV) medications given to treat acute flare-up of symptoms
    • Pills may be taken for a longer period of time if you have severe asthma that isn't responding to other treatments.
  • ]]>Epinephrine]]> —a shot given to stop an asthma attack

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Prevention

There are no guidelines for preventing asthma because the cause is unknown. However, you can help prevent asthma attacks by avoiding things that trigger the attacks. Some general guidelines include:

  • Keep windows closed.
  • Consider getting HEPA filters for your heating/cooling system and your vacuum cleaner.
  • Keep the humidity down in your house.
  • Avoid strenuous outdoor exercise during days with high air pollution, a high pollen count, or a high ozone level.
  • Get a yearly flu shot]]> .
  • Treat allergies and sinusitis.
  • Don't smoke.
  • Avoid breathing in chemicals or second-hand smoke.
  • Don't regularly use a wood-burning stove . Researchers reported that heating systems that are more efficient and non-polluting can help to reduce asthma symptoms in children. ]]>*¹]]>
  • If allergies trigger your asthma attacks, ask your doctor about allergy shots.
  • Talk to your doctor about:
    • An appropriate level of exercise for you
    • Ways track your asthma—This will help you to identify and treat flare-ups right away.