When a patient is having asthma symptoms such as wheezing or shortness of breath, the doctor is likely to ask questions about the symptoms. Questions about asthma symptoms are the first step towards an asthma diagnosis. The doctor will want to know when the patient is experiencing symptoms and what symptoms the patient is experiencing. Since the patient is probably not going to be experiencing asthma symptoms at the time of the doctor’s exam, the doctor must rely on the patient’s description of the symptoms.

The doctor may ask if the patient has noticed anything that seems to make the asthma symptoms start or if they are worse at certain times of day. Some people with asthma only have symptoms during exercise. Other people with asthma may have the worse asthma symptoms at night. Sometimes, people recognize that their asthma symptoms are worse when they are around an allergen, like animals, or when they are cleaning and exposed to dust. This information about possible triggers for asthma will not only help the doctor to determine if the person has asthma, but also what type of asthma the patient may have.

The next step in asthma diagnosis is diagnostic testing for asthma. There are different tests that a doctor may order. A peak flow test is a test that the doctor may perform during the time of the exam. The doctor may instruct the person on how to use a peak flow meter at home. The peak flow is a measure of the person’s highest speed of exhalation. The test can be repeated to see if inflammation or constriction is occurring. This can be helpful to the patient in monitoring the asthma symptoms at home.

A lung function test, also called a pulmonary function test, checks the person’s lung capacity and how well the person’s lungs are delivering oxygen to the body. A lung function test called spirometry times and measures how quickly and how much air the person can exhale. This test can determine how much airway obstruction is present. The test may be repeated after the person inhales a bronchodilator, which is a medication that reduces inflammation.

The methacholine test is similar to the spirometry, but the person first inhales a medication that will constrict the airway in someone with asthma. If the airway constricts and the person is less capable of performing breathing exercises, the person may be diagnosed with asthma. A chest x-ray may be ordered to rule out other causes of breathing problems, but it is not commonly necessary. After the doctor receives the test results, the doctor will be able to confirm a diagnosis of asthma if asthma is present.