Identifying your triggers is the first step in preventing asthma attacks. Keep a diary for several weeks, detailing all the environmental and situational factors that are associated with your asthma attacks. When you have an asthma attack (exacerbation), go back to the diary to see which factor, or combination of factors, might have contributed to it. Some common asthma triggers are not always obvious, such as house dust mites, molds, and cockroaches. Ask your doctor about allergen skin testing to determine the allergens to which you might have become sensitized. You can then take measures to minimize exposure to those allergens.
When planning vigorous exercise or exercise in cold or dry environments, prevent exercise-induced bronchospasm (EIB) by following your doctor's advice regarding pretreatment (usually with albuterol) and warm-up and cool-down periods.
Discuss with your doctor the possibility of monitoring your lung function at home. For this you'll need a peak flow meter or pocket spirometer (instruments which cost $20 to $60 and are available without a prescription). After you determine your personal best lung function (PEF or FEV1), check it again whenever you have asthma symptoms. A decline of more than 20% in lung function on a peak flow meter typically indicates that you are having an asthma exacerbation (a fall into the yellow zone) and should quickly follow your written asthma action plan to prevent a further worsening of airway obstruction.
Minimize exposure to all sources of smoke, including tobacco, incense, candles, fires, and fireworks. Do not allow smoking in your home or car, and avoid public places that permit smoking. If you smoke cigarettes, get help to quit successfully. Smoking typically makes asthma worse.
Avoid close contact with people who have respiratory cold symptoms (which suggest that they are suffering from a respiratory virus), and wash hands thoroughly after touching items which may have been handled by others with a respiratory infection.
Get a flu shot every year to protect against the flu virus, which almost always makes asthma much worse for days to weeks. Talk to your doctor about getting a pneumonia shot (Pneumovax) as well, because people with asthma are about twice as likely as others to get pneumococcal pneumonia.