Asthma Center

Asthma Diagnosis

Your primary physician can diagnose asthma. However, you may need to see an asthma specialist if:

  • You have difficulty controlling asthma
  • You've experienced a life-threatening asthma attack
  • You require specialize diagnostic tests to confirm asthma

Medical history
In order to diagnose asthma, your doctor will first review your medical history and perform a physical exam.  Your doctor will ask you about your family history of asthma and allergies. S/he may also ask whether you have asthma symptoms, and when and how often they occur, and what triggers symptoms. Your doctor may ask you about related health conditions including chronic runny nose, sinus infections, reflux disease, psychological stress, and sleep apnea. During a physical exam, your doctor will listen to your breathing and look for signs of wheezing, swollen nasal passages, and allergic skin conditions such as eczema.  Keep in mind that you can still have asthma even if you don't have these signs on the day that your doctor examines you.

Medical exams
Following a physical, the doctor may request diagnostic tests to confirm or exclude an asthma diagnosis.  The primary diagnostic tools doctors used to diagnose asthma include lung function tests.  These pulmonary function tests are used to identify the cause of breathing problems and to check for conditions including lung tissue scarring, sarcoidosis, and chronic obstructive pulmonary disease (COPD). The full range of diagnostic tests for asthma are:

Allergy testing - used to identify allergens that affect you

Blood oxygen tests - pulse oximetry and arterial blood gas are two tests used to measure the oxygen level in the blood.

Bronchoprovocation test - used to measure how sensitive your airways are. This test repeatedly measures your lung function during physical activity or after you receive increasing doses of cold air or a special chemical to breathe in.

Chest x ray - used to identify possible foreign object or other disease

EKG - used to identify possible foreign object or other disease

Lung diffusing capacity - this test measures how well oxygen passes from your lungs to your bloodstream.

Lung function test (spirometry)- this test checks how your lungs are working. This test measures how much air you can breathe in and out. It also measures how fast you can blow air out. Your doctor also may give you medicines and then test you again to see whether the results have improved.

Lung volume measurement - there are four different kinds of lung volumes and four different kinds of lung capacities.  All are measured with lung volume measurement. For example, your might perform a residual lung volume test which measures how much air you have left in your lungs after you breathe out completely.

Peak flow meter - the meter helps people with asthma track their breathing.

Other tests - Other health conditions such as runny nose, sinus infections, gastrointestinal disease, psychological stress, vocal cord dysfunction and sleep apnea can make asthma more difficult to manage. These conditions also require diagnosis and treatment as part of an overall asthma care plan.

Many of the above lung function tests may also be used to check whether a condition is getting worse. Based on your medical history, the physical exam, and results from diagnostic tests, your doctor will identify the level of asthma severity.  The diagnostic severity level of asthma will determine treatment.  Asthma may be diagnosed as:

  • intermittent asthma
  • mild asthma
  • moderate asthma
  • severe asthma

Asthma can be controlled by taking medicine and by avoiding the triggers that can cause an attack.  With proper treatment, most people who are diagnosed with asthma can expect to have few, if any, symptoms either during the day or at night.  To learn more about how to treat asthma, continue reading.

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