The first stage of asthma diagnosis is from a history of asthmatic symptoms. These symptoms include periods of coughing, wheezing, shortness of breath, or chest tightness that come on suddenly in response to specific stimulants or time periods. A history of head colds that evolve into chest congestion or take more than 10 days to recover from is pertinent. Family history of asthma or allergies may also be part of the diagnosis.
A physical exam may reveal wheezing in the chest that can be heard with a stethoscope. A device called a spirometer may be used to check the function of the airways in children over five years of age and in adults. The test measures the volume of air and the speed with which air can be blown out of the lungs after a deep breath. If the airways are narrowed from inflammation and the muscles around the airways tightening up from asthma, the results will be lower than normal. If spirometry results are normal but asthma symptoms are present, other tests are performed. A bronchial challenge test involves inhalation of a substance such as methacholine, which causes narrowing of the airways in asthma. The effect is measured by spirometry to determine is asthma is present. Children under five years of age usually cannot use a spirometer successfully. In such cases, asthma medications are often attempted as part of the diagnosis to determine if they are able to alleviate the symptoms.
Allergy testing may be performed to determine if there are specific allergens that the individual is reactive to. A device called a peak flow meter may be used every day for several weeks to measure breathing efficiency. Tests may be performed to determine the reaction of the airways to exercise. In some cases, a chest x ray or an electrocardiogram may be used to determine if a foreign object, other lung disease, or heart disease could be causing asthma-like symptoms. The results of the medical history, physical exam, and lung function tests are used to diagnose the severity of asthma and determine treatment.
|
|
Author Info: Maria Basile PhD, Thomson Gale, Gale, Detroit, Gale Encyclopedia of Genetic Disorders Part II, 2005 |