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

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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. Smoking during pregnancy is particularly harmful and places children at high risk of developing childhood asthma. Childhood viral infections are associated with later development of 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

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)
• Taking medicines such as acetaminophen

Symptoms include:

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

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

The treatment strategy for asthma is four-fold:

• Regular assessment and monitoring—Online programs aimed at helping you manage your own symptoms can improve asthma control and lung function (See American Lung Association or Asthma and Allergy Foundation of America). Staying in contact with your doctor between visits can help you stay out of the hospital and have better control of your asthma. Whether you stay in contact over the phone, through email, or through your doctor's website, good communication and symptom management is important.
• Control of contributing factors (eg, gastroesophageal reflux and sinusitis) and avoidance of allergens or irritants
• Patient education
• Medications

You and your doctor should also create an asthma action plan. This is a plan you will follow to help control your asthma and handle asthma attacks. In addition, it may be helpful to learn breathing techniques from a physical therapist.

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 a portable HEPA unit air cleaner to use in sleeping areas.
• 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 seasonal flu shot.
• Treat allergies and sinusitis.
• Don't smoke. If you are pregnant, it is very important that you do not smoke.
• Avoid breathing in chemicals or second-hand smoke. Spend time with your doctor reviewing your work, hobbies, and home activities to see if any of these may be causing or worsening your asthma.
• Don't use a wood-burning stove or fireplace, including unvented gas fireplaces. Researchers report that using closed system, non-polluting heating systems can help to reduce asthma symptoms in children.
• If allergies trigger your asthma attacks, ask your doctor about allergy shots. If you commonly have nasal symptoms (stuffy, runny, or itchy nose), treatment of these may greatly improve your asthma.
• 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.