health

The doctor performs a physical checkup and ask questions about symptoms
and when they occur. In addition, the doctor may do various tests
to help identify asthma and its causes. Some of the tests are described
below.

Allergy tests Allergy tests help identify those substances to which a
person is allergic. Skin tests are most common. Tiny amounts of possible
allergens are put on the skin, and the skin is checked to see which substances,
if any, cause a reaction. In another type of allergy test, a blood
sample is checked for certain antibodies, which are substances made in
the blood that fight foreign or harmful substances. People with allergies
may have high levels of immunoglobulin E (IgE) antibodies. However,
the blood test is generally not considered as precise as the skin test, and it
cannot check for as many allergens.

Chest x-ray An x-ray is an invisible wave that goes through most solid
matter depending on its density and produces an image on film. After
the film is developed, a special picture can be viewed that shows how the
lungs and other structures look. An x-ray can help rule out other causes
of wheezing.

Lung-function tests These tests show how well the lungs are working.
In one test, the person blows into a device called a spirometer (spi-
ROM-i-ter), which measures the amount of air going in and out of the
lungs. Another test uses a peak flow meter to measure how fast the person
can breathe air out of the lungs. A peak flow meter is a simple, hand-held
device that can be used at home. Many people with asthma use peak flow
meters regularly to check for early warning signs of an upcoming asthma
attack. Doing so gives them time to take certain medicines that can often
stop the attack.