Recognizing the Different Kinds of Asthma
Bronchial Challenge Test
If your spirometry results are normal but you have asthma symptoms, your doctor may conduct other tests to see what else could be causing them. One commonly used test is a bronchial challenge test. A substance such as methacholine, which causes narrowing of the airways in asthma, is inhaled. The effect is measured by spirometry. Children under the age of 5 usually cannot use a spirometer successfully. If spirometry cannot be used, the doctor may decide to try medication for a while to see if the child's symptoms get better.
Besides spirometry, your doctor may also recommend that you have the following to help in diagnosing asthma:
- Allergy testing to find out if and what allergens affect you
- A test that uses a handheld peak flow meter every day for 1 to 2 weeks to check your breathing (a peak flow meter is a device that shows how well you are breathing)
- A test to see how your airways react to exercise
- Tests to see if you have gastroesophageal reflux disease (GERD)
- A test to see if you have sinus disease
- Other tests, such as a chest x-ray or an electrocardiogram, may be needed to find out if a foreign object, other lung diseases, or heart disease could be causing asthma symptoms.
A correct diagnosis is important, because asthma is treated differently from other diseases with similar symptoms.
Depending on the results of your physical exam, medical history, and lung function tests, your doctor can determine the severity of your asthma. This is important, because your asthma severity will determine how your asthma should be treated.
A general way to classify asthma severity is to consider how often a person has symptoms when that person is not taking any medicine or when his or her asthma is not well controlled. Based on symptoms, the four levels of asthma severity classification are:
- Mild intermittent asthma. When your asthma is not well controlled, you have asthma symptoms twice a week or less, or you are bothered by symptoms at night twice a month or less.
- Mild persistent asthma. When your asthma is not well controlled, you have asthma symptoms more than twice a week but no more than once a day. You are bothered by symptoms at night more than twice a month. You may have asthma attacks that affect your activity.
- Moderate persistent asthma. When your asthma is not well controlled, you have asthma symptoms every day and you are bothered by nighttime symptoms more than once a week. Asthma attacks may affect your activity.
- Severe persistent asthma. When your asthma is not well controlled, you have symptoms throughout the day on most days and you are bothered by nighttime symptoms often. In severe asthma, your physical activity is likely to be limited.
Anyone with asthma can have a severe attack -- even those who have intermittent or mild persistent asthma.