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Exercise-Induced Asthma (cont.)

Exams and Tests

If you are having an asthma attack, your health care provider (whether your primary care provider or an emergency department physician) will ask you questions about your symptoms, medical history, and medications. Answer as completely as you can. He or she will also examine you and observe you as you breathe.

He or she will assess the severity of the attack. Attacks are usually classified as mild, moderately severe, or severe. This assessment is based on several factors.

Symptom severity and duration
Degree of airway obstruction
Extent to which the attack is interfering with regular activities

If you have had symptoms and are seeking medical care afterward, the health care provider will ask questions and perform tests to search for and rule out other causes of the symptoms. The evaluation will almost certainly include tests of how well you can breathe at rest and may include tests during exertion. These tests are done at rest, after 6-8 minutes of exercise, and then at regular intervals until at least 30 minutes after you have stopped exercising. Proper diagnosis is essential to ensure that the most appropriate treatment is given.

Measurements of how well you are breathing include the following:

Spirometry: The spirometer is a device that measures how much air you can exhale and how forcefully you can breathe out. The test may be done before and after you inhale a medication. Spirometry is a good way to see how much your breathing is impaired during an attack. This test must be done in the medical office; you may exercise on a treadmill or stationary bicycle.
Peak flow meter: This is another way of measuring how forcefully you can breathe out during an attack. This device is small and portable and can be used "in the field." This allows testing after 6-8 minutes of your usual activity.
Oximetry: A painless probe, called a pulse oximeter, may be placed on your fingertip to measure the amount of oxygen in your bloodstream.

No blood test can pinpoint the cause of asthma.

Your blood may be checked for signs of an infection that might be contributing to the symptoms.
In severe attacks, it may be necessary to sample blood from an artery to determine exactly how much oxygen and carbon dioxide are present in your body.

A chest x-ray may also be taken. This is mostly to rule out other conditions that can cause similar symptoms.