Some people have compared the irritated bronchial tubes of asthma to a scraped knee after a fall on the pavement. The irritants and allergens that you breathe in every day are like harsh chemicals poured on the wound. If you can avoid them, the swelling and sensitivity lessen. You will gradually notice less coughing, fewer nighttime awakenings, easier breathing, and less frequent need for medications to relieve the symptoms of asthma.

That is why a basic part of asthma management is to identify and try to avoid the triggers that make your symptoms flare. You may be able to minimize or perhaps even eliminate the need for some asthma medicines by identifying those things in your environment — particularly in your home — that make your asthma worse and either remove them or reduce your exposure to them.

If you have had asthma for any length of time, you are likely to know what your particular asthma triggers are. You may know, for example, that if you run to catch the bus on a cold day, you will begin to cough and breathe heavily once you sit quietly in your bus seat. Or perhaps if you are exposed to tobacco smoke or strong perfumes, you can count on feeling your chest tighten and having to use your asthma medications.

Many common triggers are inhaled directly into the airways, but it is important to know that some triggers are not inhaled. For example, medications taken by mouth, changes in hormone levels in your body, and even strong emotions can lead to worsening asthma symptoms. Common irritants and physical states that can trigger asthma symptoms include vigorous exercise (especially in cold air), smoke (from tobacco and other sources), air pollution, certain medications, and respiratory infections. Other triggers are based on individual allergic sensitivities and therefore vary from one person to the next. For instance, some people with asthma find that their symptoms worsen in springtime, when many tree and grass pollens are plentiful, while other people are unaffected. Most of these allergens that worsen asthma symptoms are airborne and cause trouble when you inhale them. Common examples include dust mites, cat and dog dander, bird feathers, and mold and mildew. Many allergic triggers are encountered primarily indoors, whether at home, work, or school. If you are uncertain about your allergic sensitivities, allergy testing can help to identify those things that cause you to have an allergic reaction.

To minimize your exposure, start by thinking about what your own asthma triggers are. Consider what you are doing and where you are when you develop asthma symptoms. For example, do you begin to cough, wheeze, or feel chest tightness when you exercise or when you visit your friend who has several pet cats? Once you have made a list of potential triggers, do an inventory to identify those triggers in your environment and take steps to eliminate or minimize them. Some suggestions for dealing with the most common asthma triggers follow.

Allergy tests and shots

If you are left wondering about possible allergic triggers, even after paying attention to when your asthma gets better or worse, consider being tested for allergies. There are two types of allergy tests. One is a blood test, known as RAST (for radioallergosorbent test), that measures blood levels of IgE antibodies to specific allergens. Another option is an allergy skin test, in which a technician scratches or pricks your skin and exposes it to a drop of solution that contains an allergen. If a rash or hive develops soon afterward, that indicates an allergic reaction to the particular substance. Usually your reaction to multiple allergens is tested at one time.

If you discover you are allergic to one or more substances, you can try to avoid them in order to prevent asthma symptoms. You and your doctor may also want to discuss treatment of your asthma with allergy shots, properly called allergen immunotherapy, typically administered by allergists. Allergy shots are different from other treatments because they can modify the basic immune process by halting the immune system’s reaction to the allergen.

The jury is out in the medical community on the wisdom of allergy shots for people with asthma. Some patients report benefit from allergy shots, while others feel no difference or even worsening symptoms. This topic is still being investigated, but some studies have shown that select patients with allergic asthma have an improvement in symptoms and lung function with this therapy. There are possible side effects of allergy shots, and this treatment is not for everybody. Most expert guidelines suggest that immunotherapy be considered only after a trial of strict avoidance of environmental triggers and typical asthma medications. It is likely that only certain asthma sufferers benefit from allergy shots, and that the shots are more effective at treating some types of allergic sensitivities than others.

Dust mites

Dust mites are tiny bugs that are typically found in mattresses, carpets, and upholstered furniture — anywhere dust accumulates. These creatures are invisible to the naked eye, and they do not bite. However, they leave droppings behind in the dust that trigger a reaction in many people with asthma. It is impossible to completely eliminate dust mites and their droppings from your home, but you can take steps to reduce your exposure, particularly focusing on your bedroom. These steps are unlikely to work if you only focus on one or two of them, but an approach which uses several strategies is likely to decrease exposure to these allergens:

  • Wash sheets, bedding, and any fabric curtains weekly in hot water.
  • Zippered allergen-impermeable wraps can be used to cover your pillows, mattress, and box spring, keeping the allergenic material from rising into the air.
  • Install window blinds that can be wiped clean.
  • Remove carpeting from the bedroom.
  • Put clothes away in closets and drawers.
  • Eliminate dust collectors from tables and other surfaces.
  • Wet-mop rather than sweep.
  • Use special filter bags in your vacuum cleaner or a HEPA (for high-efficiency particulate air) vacuum, which contains a special filter to trap allergens, to prevent dust particles escaping through the exhaust system.
  • Attempt to decrease the humidity in your environment. Avoid humidifier use and consider opening windows or using the air conditioner.

Work triggers

The workplace can be filled with asthma triggers. Certain occupations are particularly difficult, including many jobs in manufacturing, construction, and food processing, because of exposure to dust and chemicals. If you experience symptoms related to an exposure at the workplace, it is important to discuss this with your physician. It may be necessary to carry out specific testing during and after work in order to confirm the diagnosis and identify the trigger. Leaving that particular line of work is often the best option, but it may be possible to simply move to a different area in the workplace. The use of a respirator mask is sometimes possible as an alternative, but the specific details of work related asthma should be discussed in detail with your physician.



Virtually everyone with asthma will experience some degree of bronchial constriction during or following exercise if the level of physical exertion is sufficiently intense. Even so, it is important to exercise on a regular basis. Not only is exercise good for your overall health, but some people with asthma find that getting into good physical shape can make breathing easier and decrease your sensitivity to asthma triggers.

Exercise triggers asthma symptoms because it forces you to breathe more deeply and heavily than you do when you are at rest. As large volumes of air are drawn through the bronchial tubes and deep into the chest, the bronchial tubes give up heat and moisture to warm and humidify the incoming air. This causes the bronchial tubes to cool and dry out. The bronchial muscles contract in response, narrowing the airways and making it difficult to breathe. Although exercise in any climate can trigger asthma symptoms, cold, dry air is the strongest stimulus to bronchial narrowing.

If exercise brings on your asthma symptoms, it may indicate that your asthma is not well controlled, and you may need to step up controller therapy to reduce your exercise-related symptoms. If you still experience exercise-induced breathing problems even though your asthma is otherwise well controlled, or if the only time you experience asthma symptoms is when you exercise, take a medication before exercising to block bronchial muscle constriction. You can take a quick-acting bronchodilator, such as albuterol or pirbuterol, 5 to 10 minutes before exercise. Alternative preventive treatments are leukotriene modifiers or cromolyn.

A variety of other strategies are also effective in preventing an asthma attack after exercise:

  • Exercise indoors, where the climate is controlled.
  • On a cold day, wear a cold-weather face mask or wrap a scarf around your mouth and nose to trap a little bit of warm, moist air in front of your face.
  • Warm up before exercising; this often helps to reduce symptoms.


Medication triggersFamily Practice, asthma, wellness, find a doctor, health education, family doctor, female doctor office

Certain medicines can also be asthma triggers. Everyone with asthma should avoid the group of medicines called beta blockers, used to treat heart disease, high blood pressure, and glaucoma. Other medication options for these conditions, such as calcium channel blockers, are usually available. Beta blockers — especially the “nonselective” ones such as propranolol (Inderal) — affect the lungs as well as the heart. They have the exact opposite effect of bronchodilators and therefore prevent narrowed airways from dilating. If use of a beta blocker is crucial — such as after a heart attack — you and your doctor may be able to find a “selective” beta blocker that acts more directly on the heart and blood vessels and has minimal lung effects. Selective beta blockers include atenolol (Tenormin) and metoprolol (Lopressor). Some people with asthma can use such medications safely without having their symptoms worsen, but the best way to find out is by trying the medication under your doctor’s supervision.

Angiotensin-converting–enzyme (ACE) inhibitors such as lisinopril (Prinivil, Zestril, others) and enalapril (Vasotec), also used to treat high blood pressure and heart disease, may indirectly trigger increased symptoms in some people with asthma. Many patients with asthma are able to safely take these drugs, but your physician should be aware that you have asthma when starting you on these medications. About 1 in 10 people taking an ACE inhibitor develops a troublesome cough. If you are taking an ACE inhibitor and develop a cough, talk with your doctor.

Common over-the-counter pain relievers such as aspirin and the group of medicines known as nonsteroidal anti-inflammatory drugs (NSAIDs) — a category that includes ibuprofen (Advil, Motrin, others) and naproxen (Naprosyn, Aleve) — can also trigger symptoms in anywhere from 3% to 5% of people with asthma. If your asthma is made worse by aspirin or one of the NSAIDs, it is imperative that you avoid all drugs in this category. Acetaminophen (Tylenol) is generally safe for use if you have aspirin-sensitive asthma. Ask your physician which prescription medications are appropriate.


Hormonal changes

Between 20-40% of women experience worsening asthma symptoms prior to or during menstruation. We don’t know exactly why, but it is likely related to fluctuations in hormone levels. The ideal therapy for women who experience these symptoms is not clear, but women should be aware that their asthma way worsen at certain times during their menstrual cycles, and they should discuss treatment strategies with their physicians.

One-third of women with asthma also experience worsening of their symptoms during pregnancy. Again, this is likely related to changes in hormone levels. Asthma can be particularly challenging to manage during pregnancy because worsening symptoms can put the fetus at risk and some medications are safer than other during this time. If you have asthma and are pregnant or considering pregnancy, discuss your asthma treatment with your physician.


Mold and mildew

Mold and mildew can grow indoors in persistently damp places. Common locations are the basement, around the kitchen sink, and in bathrooms. If you have asthma, you may be allergic to mold. (But don’t worry that you are falling victim to “toxic” mold. In spite of the spate of news reports about this problem, any shortness of breath or other symptoms you experience most likely are related to your underlying allergic sensitivity to mold rather than to the nature of the mold itself. In fact, there is no scientific consensus about whether toxic mold even exists. If you have a weakened immune system due to an underlying cancer or immunosuppressive drugs you should speak to your physician about the risks of a true fungal infection) You can usually detect mold growth by seeing or smelling it. Take these steps to eliminate mold:

  • Wash any moldy or mildewed surfaces with detergent and water and dry the area completely.
  • If carpets, upholstery, furniture, or porous walls have been contaminated with mold these materials should be removed and replaced.
  • If your basement tends to become flooded with water, avoid having carpeting on the cement floor.
  • Reduce indoor humidity to less than 50% by increasing ventilation and using a dehumidifier if necessary.
  • Install an exhaust fan in the bathroom or keep windows open to allow air to circulate.
  • Repair any kitchen or bathroom leaks quickly.
  • Clean sink surfaces and floors regularly.


Petshealth education, family practice, doctor's office, find a doctor, local doctor, doctor near by, find a physician

Warm-blooded animals — such as cats, dogs, rabbits, and birds — produce substances on their skin, fur, and feathers, and even in their saliva and urine, that are common allergic triggers for people with asthma. Even more exotic pets, such as reptiles and insects, may be triggers for your asthma. If pets make your asthma worse, try the following:

  • If you want a pet, consider fish or other animal without fur that has a low likelihood of causing symptoms..
  • If you already have a pet cat, dog, or bird, consider finding it a new home.
  • If you don’t want to give up your pet, try to keep the animal outside of your house. This is much more effective than simply keeping the pet in another area of your home.
  • Vacuum frequently, preferably with a HEPA vacuum cleaner and consider installing a house filtration system if you use forced hot air heat.
  • Use a free-standing HEPA filter in the bedroom or family room to reduce allergen exposure. This is most effective if the allergen reservoir (the pet itself, carpets, upholstered furniture) is removed, because these filters create air currents that may actually increase the amount of allergen in the air if the reservoir is still present.



Pollen is a powdery substance given off by seed plants and trees in the spring, summer, and fall. If you are allergic to outdoor pollens, you cannot fully avoid them without living in a bubble. But you can lessen your exposure to pollens, at least while you are indoors. Here are some suggestions:

  • Install an air conditioner, which filters the outdoor air and cools the inside so that windows can be kept shut on hot summer days.
  • As an alternative, install a window fan with attached filter.
  • Remove your shoes and outer garments after coming into the house from outdoors; this will help you avoid carrying pollen indoors.
  • Consider showering before bed in order to remove allergens from your hair and skin that may contaminate your bedding.


Temperature and weather

Both hot, humid air and cold, dry air may lead to constriction of the breathing tubes and worsening of asthma symptoms. In addition, certain conditions such as thunderstorms lead to an increase in environmental pollen. It is important to be aware of these possible triggers and pay attention to the weather changes that may impact your asthma.

  • Use masks or scarves in cold weather in order to trap moisture and minimize the effect of the cold, dry air.
  • Consider using a rescue medication prior to exercising in cold, dry air or when a thunderstorm is beginning.


Respiratory infections

Colds, ear infections, and sinus infections are common triggers, and they often cause severe flare-ups. It is impossible to avoid every cold virus, but you can take steps to lessen your chances of developing a respiratory infection that will worsen your asthma. Here are some suggestions:

  • Wash your hands frequently, as touching any contaminated surface (including doorknobs or telephones) can expose you to a cold virus.
  • Avoid people with respiratory infections when possible.
  • Avoid touching your eyes, mouth, or nose until you have washed your hands.
  • Get a flu shot every fall to avoid contracting influenza.
  • Get a pneumonia vaccine (you do not need to receive this vaccine every year).



Mice and rats produce antigens in their urine that can trigger asthma symptoms. This is more frequently an issue in urban areas. If you suffer from asthma and believe you may have rodents in your house consider the following:

  • Hire a professional exterminator to investigate and remove rodents from your house.
  • Keep food and trash in covered containers
  • Keep floors and countertops clean.
  • Seal all cracks in walls, floors, and doors.



Cockroaches are an unfortunate fact of life for many people who live in apartment buildings, particularly in urban areas. The saliva, eggs, and waste of cockroaches contain allergens that can trigger asthma attacks. Take these steps to deal with roaches:

  • Use roach traps or hire a professional exterminator to rid your home of a roach infestation.
  • Store food in airtight containers whenever possible.
  • Clean dishes after each meal.
  • Clean the kitchen sink and countertops frequently to remove any traces of food or standing water.
  • Keep trash covered.



Tobacco smoke of any kind can irritate your breathing passages. Many people with asthma are also sensitive to other sources of smoke, such as candles, incense, and wood fires. Do the following to protect yourself:

  • Don’t smoke cigarettes, cigars, or a pipe.
  • Don’t allow smoking in your home.
  • Install an exhaust fan over the stove to remove cooking smoke, or open windows while cooking.
  • Do not use woodstoves or fireplaces.
  • Avoid secondhand smoke in public places.