What Triggers Asthma Episodes?

Triggers are substances or situations that cause an asthma episode or worsening of day to day asthma symptoms. One goal of asthma management is to eliminate as many triggers as possible. Each child has their own set of triggers. It is often hard to identify the event that causes a particular episode because a combination of factors may cause the episode. By making careful observations over time, a family can usually identify most triggers. Triggers such as cigarette smoke, dust, aerosol sprays or strong odors, can be identified and then eliminated or avoided. Other triggers, such as air pollution or pollen are much harder to avoid but medications can help prevent the trigger from setting off an asthma episode. The following are examples of types of triggers and some ways to deal with them.


Allergens are substances which commonly cause allergic reactions. Some allergens are animal dander, pollens, house dust mites, molds, and rarely some foods. Contact with these substances can cause a chemical reaction to take place in the body which can trigger asthma.

Cigarette Smoke

No smoking

Smoke is an irritant to your child’s lungs. It can set off spasms in the air passages of the lungs and cause episodes of coughing and wheezing.

Even if smoke does not cause an asthma episode in your child, breathing second-hand smoke can affect the defenses of the lungs. Tobacco smoke contains over 4,000 chemicals, most of which are toxic and carcinogenic. Recent studies have suggested that children of smokers are twice as likely to develop asthma as the children of nonsmokers and that even apparently healthy babies born to women who smoked during pregnancy have abnormally narrowed airways, which may predispose them to asthma and other respiratory disorders. Second-hand smoke is smoke in the air from others who smoke. Second-hand smoke steps up the heartbeat, increases the blood pressure, and robs the body of the oxygen it needs. Some studies show that colds, ear infections, and breathing problems are twice as common among young children who breathe smoke at home compared with those in smoke-free homes.

Your smoking can affect your child’s behavior throughout their life. Most teenagers who smoke, for example, have parents who smoke. Cigarette smoking is a major cause of severe lung diseases like chronic bronchitis, emphysema, and lung cancer. (Marijuana and cocaine also cause severe lung disease)

We strongly recommend you stop smoking completely.¬†If you feel you cannot stop NOW, we ask that you do not smoke or allow smoking in your child’s home or in the car.¬†Smoking in a separate room, keeping the windows open, or using an air cleaner are not acceptable choices.

Look in the smoking cessation section for links to classes and information to help you QUIT NOW!


Exercise is a common trigger of symptoms such as coughing or wheezing in asthmatic children. Some children may complain that they tire more easily than their friends when they play. In most children, exercise of at least 5 minutes without a warm-up period is necessary to trigger asthmatic symptoms.

Taking inhaled medication before exercise can block asthma symptoms. The child should start off at a comfortable level of exercise and work slowly toward more difficult levels. The key with asthmatic children and exercise is to take medication and to warm up before activity. Talk with your child’s health care provider if periods of coughing and wheezing occur with exercise and your medicine doesn’t help. Parents and teachers need to help children learn to manage such situations. Children with asthma can and should get regular exercise since research shows that these children benefit from exercise.


Often asthma becomes worse following changes in the weather. There is, however, no one type of climate which is good or bad for all asthmatic children, although damp weather tends to aggravate asthma regardless of temperature. Changes in the weather can cause changes in air quality in areas with pollution, car emissions, or pollens. Some children may have problems with their asthma on cold, rainy days and others may be bothered more by hot, dry weather. The goal of therapy in these cases is to control irritability of the airways, not to try to isolate the child from the environment.

Hormone Changes

When the balance of these body chemicals changes (especially during puberty, before menstruation, and during pregnancy) asthmatic symptoms may change. The symptoms may become either better or worse.

Respiratory Infections and Childhood Diseases

Colds and respiratory tract infections are common triggers of asthma symptoms, especially in younger children. Some preventive measures which should be taken with all children include plenty of sleep, a balanced diet, regular physical activity, plenty of fluids, avoidance of situations where people may be sick, and good hand washing. When colds or upper respiratory infections consistently trigger asthma episodes, the child may need to add medications at the onset of the cold or upper respiratory infection. Viruses, which cannot be treated with antibiotics are the cause of most infections that trigger asthma.

Emotional Situations

Emotions can be involved in the triggering of asthmatic symptoms. No amount of emotional stress, however, can cause asthma unless a child already has abnormally reactive airways.

If emotional situations trigger your child’s asthma, try to observe carefully to see if the situations can be avoided or handled differently.

Do not let the possibility of asthmatic symptoms restrict either the child’s fun or the discipline you see as necessary. If the child has an asthma episode when excited or upset, help the child calm down and relax. If necessary, use medications as directed by your health care provider.