| Risk Factors
Asthma is a chronic disease that affects the function and lining of the airways or tubes of the lungs. It narrows the airways and makes it difficult to breathe.
Inflamed Bronchus in the Lungs
Copyright © Nucleus Medical Media, Inc.
Asthma may be caused by a combination of factors including environment, genetics, and biology.
Asthma symptoms are caused by an increased sensitivity of the airways to certain triggers. The triggers cause the lining of the airways to swell and produce extra fluid called mucus. At the same time, the muscles around the outside of the airway tighten in response to the irritation. All of these reactions narrow the airways and make it difficult to breathe. This response is often referred to as an asthma attack.
Possible triggers of an asthma attack in a person with asthma include:
- Viral illness
- Cold weather
- Gastroesophageal reflux disease
- Sulfites used in dried fruits and wine
Medications, such as
, and beta-blockers
Exposure to irritants or allergens, including:
- Cigarette smoke
- Smoke from a wood-burning stove
- Pet dander
- Mold and mildew
- Smog or air pollution
- Perfumed products
Factors that may increase you risk for asthma include:
Regularly breathing in cigarette
(including second-hand smoke)
- Regularly breathing in industrial or agricultural chemicals
- A family member who has asthma
- History of multiple respiratory infections during childhood
- Being overweight
- History of wheezing or asthma as a child
- Having allergies
- Your mother smoked during pregnancy
- Tightness in the chest
- Trouble breathing
- Shortness of breath
- Chest pain
- Limited exercise tolerance, difficulty keeping up with peers
The doctor will ask about your symptoms and medical history. A physical exam will be done.
Your doctor may also do some tests to measure lung functions. They 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
- Reversibility testing—tests for relief of airflow obstruction when medicines such as albuterol or ipratropium are given.
- Bronchoprovocation tests—lung function tests performed after exposure to methacholine to stimulate asthma;
can help to confirm asthma in unclear cases
- Exhaled nitric oxide (a marker of airway inflammation)—to help monitor asthma control
Your doctor may also do some
allergy tests. The test will help determine if allergies are causing symptoms. The test may include skin pricks or blood tests.
strategy for asthma includes:
Avoidance of allergens and irritants and control of contributing factors (such as
- Regular assessment and monitoring
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.
These medications are used to control the chronic swelling. It will help to avoid asthma attacks, but will not treat an existing attack:
- Inhaled corticosteroid—used daily to reduce inflammation in your airways
Long-acting beta agonists—(such as inhaled
) used daily to prevent asthma attacks. In most cases, prescribed with 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.
- Cromolyn sodium
or nedocromil sodium inhaler—used daily to prevent asthma flare-ups or to prevent exercise-induced symptoms
—taken daily to help prevent asthma attacks
—a monoclonal antibody against immunoglobulin E (IgE), given as an injection under the skin, used along with other medications
for patients with harder to control asthma
—taken daily to help prevent asthma attacks, not as commonly used because of interactions with other drugs
These medications are used to treat an existing asthma attack:
Quick-acting beta agonists—(such as inhaled
) 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
, that function as a bronchodilator, typically only used in an emergency setting
Corticosteroids—pills, injections, or IV medications given to treat acute flare-up of symptoms
- Pills may be taken for a longer period of time. They may also be recommended to help control asthma if you have severe asthma that isn't responding to other treatments.
Prevention is an important step in asthma care. Allergy avoidance can be very effective with asthma that is exacerbated by allergens. Some general tips for allergen avoidance include:
- Avoid outside activities if there are high levels of air pollution, pollen, or mold spores.
- Keep your windows closed during seasons with high pollen or mold spores. Air conditioning may help filter out allergens during warm seasons.
- 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.
- Have someone else vacuum for you. Avoid a room that has been freshly vacuumed. If you do vacuum, use a dust mask.
- Keep the humidity down in your house. This may help prevent the growth of mold.
- Treat allergies and sinusitis as recommended.
If allergies trigger your asthma attacks, ask your doctor about allergy shots. If you commonly have stuffy, runny, or itchy nose, these shots may improve your asthma.
In addition, it may be helpful to learn breathing techniques or doing breathing exercises. Ask your doctor for recommendations.
Your asthma plan may need to be adjusted to adapt to changes in your life or health. Staying in contact with your doctor between visits can help you have better control of your asthma. Contact may occur over the phone, through email, or through your doctor's website.
Online programs aimed at helping you manage your own symptoms can improve asthma control and lung function. Some examples of programs include
American Lung Association
Asthma and Allergy Foundation of America.
There are no guidelines for preventing asthma because the cause is unknown. However, you can help prevent asthma attacks by avoiding things that trigger your attacks.
Triggers can vary from person to person but some general guidelines include:
- Avoid strong chemicals or odors like perfume.
- 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. Colds and flus can exacerbate asthma.
- Don't smoke. If you are pregnant, it is very important that you do not smoke.
- Avoid secondhand smoke. Do not allow anyone to smoke in your home.
- Don't use a wood-burning stove or fireplace, including unvented gas fireplaces.
- If cold weather triggers your asthma, avoid strenuous activities in cold weather. If you must, use a scarf or mask to warm the air before it reaches your lungs.
Talk to your doctor about:
- An appropriate level of exercise for you
- Ways to track your asthma to help identify and treat flare-ups right away.
- Your work, hobbies, and home activities to see if any of these may be causing or worsening your asthma.
Asthma in adults and adolescents. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed/what.php. Updated September 7, 2012. Accessed September 13, 2012.
Asthma exacerbation in adults and adolescents. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed/what.php. Updated August 27, 2012. Accessed September 13, 2012.
Asthma overview. Asthma and Allergy Foundation of America website. Available at:
http://www.aafa.org/display.cfm?id=8. Accessed September 13, 2012.
Breathing exercises and or retraining techniques in management of asthma. Agency for Healthcare Research and Quality website. Available at:
http://www.effectivehealthcare.ahrq.gov/ehc/products/222/1251/CER71_BreathingExercises_FinalReport_20120905.pdf. Accessed September 13, 2012.
Bope ET, Rakel RE, Kellerman RD.
Conn's Current Therapy 2010. Philadelphia, PA: WB Saunders Company; 2010.
Control of environmental factors and comorbid conditions that affect asthma. National Heart Lung Blood Institute website. Available at:
http://www.nhlbi.nih.gov/guidelines/asthma/06_sec3_comp3.pdf. Accessed September 13, 2012.
Medical effects of mold exposure. American Academy of Allergy, Asthma & Immunology website. Available at
http://www.aaaai.org/media/resources/academy_statements/position_statements/mold.pdf. Accessed September 14, 2012.
Kleigman RM, Jensen HB, Behrman RE, et al.
Nelson Textbook of Pediatrics.
18th ed. Philadelphia, PA: Saunders Elsevier; 2007.
Subbarao P, Mandhane PJ, Sears MR. Asthma: epidemiology, etiology and risk factors.
CMAJ. 2009 October 27; 181(9): E181-E190.
Sublett JL, Seltzer J, Burkhead R, et al.; American Academy of Allergy, Asthma & Immunology Indoor Allergen Committee. Air filters and air cleaners: rostrum by the American Academy of Allergy, Asthma & Immunology Indoor Allergen Committee.
J Allergy Clin Immunol. 2010 Jan;125(1):32-8.
Flu and people with asthma. United States Centers for Disease Control and Prevention. US Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/asthma/. Updated October 5, 2011. Accessed September 14, 2012.
10/29/2008 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Howden-Chapman P, Pierse N, Nicholls S, et al. Effects of improved home heating on asthma in community dwelling children: randomised controlled trial.
2008 Sep 23.
1/6/2009 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Levenson M. Long-acting beta-agonists and adverse asthma events meta-analysis. Joint Meeting of the Pulmonary-Allergy Drugs Advisory Committee, Drug Safety and Risk Management Advisory Committee and Pediatric Advisory Committee. December 10-11, 2008.
2/17/2009 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Bailey EJ, Cates CJ, Kruske S, et al. Culture-specific programs for children and adults from minority groups who have asthma.
Cochrane Database Syst Rev.
7/6/2009 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Thomas M, McKinley RK, Mellor S, et al. Breathing exercises for asthma: a randomised controlled trial.
2009;64:55-61. Epub 2008 Dec 3.
9/2/2009 DynaMed Systematic Literature Surveillance
http://www.dynamicmedical.com/what.php: Van der Meer V, Bakker MJ, van den Hout WB, et al. Internet based self-management plus education compared with usual care in asthma: a randomized trial. Ann Intern Med.
10/8/2010 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Ducharme F, Chroinin M, Greenstone I, et al. Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children.
Cochrane Database Syst Rev.
1/4/2011 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: McLean S, Chandler D, Nurmatov U, et al. Telehealthcare for asthma.
Cochrane Database Syst Rev.
11/12/2013 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Freitas DA, Holloway EA, et al. Breathing exercises for adults with asthma. Cochrane Database Syst Rev. 2013 Oct 1;10:CD001277.
Last reviewed September 2013 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.