Asthma Health Article

Physical examination

Apart from listening to the patient's chest, the examiner should look for maximum chest expansion while taking in air. Hunched shoulders and contracting neck muscles are other signs of narrowed airways. Nasal polyps or increased amounts of nasal secretions are often noted in asthmatic patients. Skin problems like atopic dermatitis or eczema indicate that the patient has allergic problems. A family history of asthma or allergies can be a valuable indicator. The diagnosis may be strongly suggested when typical symptoms and signs are present.

Spirometry and chest x ray

Spirometry can confirm a diagnosis of asthma by measuring lung function: how much air the lungs can hold and how much they can expel. Asthma patients typically have normal lung volumes with diminished flow rates. Repeating the test after the patient inhales a bronchodilator will show whether the airway narrowing is reversible, a finding that distinguishes asthma from other obstructive diseases like emphysema.

Often patients use a related instrument, called a peak flow meter, to monitor asthma severity at home. Because this device measures the strength with which air is exhaled, it can detect narrowed airways at the earliest stage, before an attack becomes full blown. This allows the patient to take the appropriate medication and diminish or avoid the episode.

Determining what triggers asthma attacks can be difficult. Skin testing may be helpful, although an allergic skin response does not necessarily mean that the allergen being tested is causing the asthma. Once a specific allergen is suspected, a blood test can be run to check for IgE antibodies, since the immune system always produces an antibody in response to an allergen. This will show if the patient is sensitive to a particular allergen. If the diagnosis is still in doubt, the patient can inhale a suspect allergen while using a spirometer to detect airway narrowing, a test called "allergen challenge." Spirometry may also be repeated after a bout of exercise to confirm or refute the diagnosis of exercise-induced asthma. A chest x ray may help to rule out other pulmonary disorders, or confirm findings particular to asthma.