Tests and Diagnosis for Asthma

Asthma is diagnosed by a health care provider based on your medical history and physical exam. Often, your health care provider will make the diagnosis based on your history of lung symptoms and evidence of expiratory airflow limitation, which is when the flow of air is lower than normal when breathing out. Sometimes your doctor will order test results to help with the diagnosis of expiratory airflow limitation. Asthma is most commonly diagnosed and managed by primary care physicians, but, depending on the severity of your asthma, your doctor may refer you to see an asthma specialist. Your health care provider will determine the severity of your asthma, whether it is intermittent, mild, moderate or severe, in order to choose appropriate treatments.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

What Will My Health Care Provider Ask About My Medical History?

Your health care provider may ask about your history and whether anyone in your family has asthma, allergies or eczema. Your health care provider will ask you details of your asthma symptoms and when and how often they occur. He or she will likely ask about other health conditions that may coexist with and affect your asthma, such as whether you have sinus infections, seasonal allergies, reflux disease, psychological stress, sleep apnea, depression, anxiety or obesity.

What If I Only Have a Cough?

Sometimes cough is the only symptom for asthma. This can be due to cough variant asthma, which produces cough and airway hyperresponsiveness. Sometimes chronic cough can be due to conditions other than asthma, such as a cough from postnasal drip, chronic sinusitis, reflux, vocal cord dysfunction or allergic bronchitis.

What If I Am a Current or Former Smoker?

Your health care provider may ask about whether you are a current or former smoker. Asthma and chronic obstructive pulmonary disease (COPD) may coexist and overlap (asthma-COPD overlap syndrome). Individuals with asthma-COPD overlap syndrome have worse outcomes than from asthma or COPD alone, so your doctor may try to differentiate between the two.

What Will My Health Care Provider Look For on a Physical Exam?

Your health care provider will listen to your breathing with a stethoscope. He or she will listen for wheezing or other abnormal lung sounds and check for runny nose, swollen nasal passages, allergic conjunctivitis and eczema.

Are There Tests for Asthma?

Many health care providers can diagnose asthma based on just the medical history and physical exam. Your health care provider may consider ordering a lung function test, such as spirometry, which checks how your lungs are working. The test measures how much air you can breathe in and out and how fast you can blow air out. Lung function tests can help diagnose asthma and determine severity. Follow-up lung function tests after treatment can help doctors determine whether treatment regimens are working. Other tests that your health care provider could order include allergy testing to see if any allergens affect you and could trigger your asthma, tests to look for coexisting conditions like reflux, vocal cord dysfunction or sleep apnea. Sometimes health care providers order chest X-rays.

How Do You Diagnose Asthma in Children?

Diagnosing asthma in young children can be difficult for many reasons. First, many children with asthma develop symptoms before the age of 5, but it can be difficult to differentiate asthma from viral illnesses that trigger wheezing, such as bronchiolitis, colds or other lung infections. A young child may be more likely to wheeze because his or her airways are smaller. It is also harder to diagnose asthma in young children because they are too young to cooperate with lung function tests.