Asthma Diagnosis

Diagnosing Asthma

To diagnose asthma, your doctor will talk to you about your personal and medical history. They may ask if you have a family history of allergies and asthma and will perform a physical exam. You may need a lung function test and other tests, which can be done easily in their clinic. If you or your child are having problems breathing on a regular basis, visit a doctor (or other health care provider like a nurse practitioner) right away.

How Do Doctors Diagnose Asthma?

Personal and medical history: Your doctor will ask questions to understand your symptoms and their causes. Bring notes to help you answer your doctor’s questions. Be ready to answer questions about:

• Your family history of asthma and allergies (if possible)
• Medicines you take and how they affect you
• Your lifestyle
• Current physical issues, including symptoms
• Other conditions and specific concerns, including all previous medical conditions you have had in the past

For example, if you have a history of allergies or eczema, you have a higher chance of having asthma. Also, a family history of asthma, allergies, or eczema increases your chance of having asthma. This information can help your doctor make a diagnosis of asthma.

Tell your doctor about anything at home, school, or work that triggers or worsens your asthma. For example, these might include pet dander, pollen, dust mites, mold, or cockroaches. Also, irritants in the air including air pollution, cleaning chemicals, and tobacco smoke may cause asthma symptoms.

The doctor may also ask if you get chest symptoms when you:

• Get a head cold
• Exercise
• Sleep at night
• Use specific medicines (such as NSAIDs)
• Are under increased amounts of stress
• Notice major changes in the weather and seasons

Physical exam: Your doctor will do a physical exam to look for signs of asthma or other related conditions. They will look at your ears, eyes, nose, throat, skin, and listen to your chest and lungs. They will measure your height and weight to look at your overall health and use it when performing and reading your lung function tests. They will also use a device called a pulse oximeter. It goes on your finger and measures the level of oxygen in your blood. You may also need an X-ray of your lungs or sinuses.

Lung function tests: To confirm asthma, your doctor may have you take one or more breathing tests known as lung function tests (also called pulmonary function tests). Lung function tests detect how well you inhale (breathe in) and exhale (breathe out) air from your lungs. These tests measure your breathing including lung capacity (how much air your lungs can hold) and if there may be some obstruction (narrowing or blockage) in the airways.

Lung function tests are often done before and after inhaling a medicine known as a bronchodilator [brahn-ko-DIE-ah-lay-tor]. This medicine opens your airways. If your lung function improves a lot with use of a bronchodilator, you could have asthma. Your doctor may prescribe a trial with asthma medicine to see if it helps.

Common lung function tests used to assess your airways include:

• Spirometry: A type of lung function test that measures how much air you breathe in and out and how fast you breathe out
• FeNO test (exhaled nitric oxide): A test that helps measure inflammation (swelling) in your airway.
• Bronchial provocation or “trigger” tests: Tests that measure if your lungs are sensitive to certain irritants or triggers (such as chemicals or allergens)

Allergy tests: A visit with an allergy specialist may be beneficial. Most people with asthma have allergies that trigger or worsen their asthma. Some common examples include pollen, pet dander, dust mites, and mold spores.

Blood tests: Your doctor may order blood tests to check your immune system. They will check the levels of a white blood cell called eosinophils [EE-oh-sin-oh-FILLZ] and an antibody called immunoglobulin E (IgE). If your levels are high, this may be a sign of severe asthma.

Will My Doctor Test for Conditions Other Than Asthma?

If your doctor thinks you have something other than asthma or related to asthma, they may run other tests. These might include a chest X-ray, acid reflux test, sinus X-ray, or other specialized tests. Your doctor may also perform allergy tests (blood or skin tests). Allergy tests are not used to find out if you have asthma. But if you have allergies, they may trigger your asthma.

There are other conditions that have similar symptoms to asthma. Your health care provider may also check you for conditions such as:

• Abnormal airways
• Acid reflux
• Cystic fibrosis (usually diagnosed at a young age)
• Chronic obstructive pulmonary disease (COPD – which is usually diagnosed in adults)
• Pneumonia or bronchitis
• Bronchiolitis (lung infection) most often caused by RSV
• Immune disorders
• Nasal polyps
• Vocal cord dysfunction (abnormal vocal cords)

What Are the Different Levels and Types of Asthma?

There are 4 levels of asthma, based on the severity of your asthma. How often you have symptoms, and your lung function determines your asthma level. Your doctor will ask you questions such as:

1. How often do you have symptoms?
2. How often do you wake up at night from coughing or trouble breathing?
3. How often do you have trouble breathing?
4. Do you have trouble doing your daily normal activities including exercise?
5. How often do you use a quick-relief (rescue) inhaler?
6. How often have you had to go to the emergency room or be admitted to the hospital because of asthma symptoms?

The answers to these questions help to determine the severity of your asthma. There are different treatment options if your asthma is intermittent (occasional) or persistent (happens regularly).

• Intermittent asthma: You have symptoms less than 2 times a week and wake up less than 2 nights a month. You use quick-relief medicine (like albuterol) 2 or fewer days per week. You can do all your normal activities. Your lung function is normal.
• Mild persistent asthma: You have symptoms 2 or more days a week and wake up 3 to 4 nights a month. You do not have daily symptoms. You use quick-relief medicine more than 2 days out of the week. Your symptoms affect some of your daily activities. Your lung function is mostly normal.
• Moderate persistent asthma: You have symptoms at least every day and wake up 1 or more nights a week. You need your quick-relief medicine daily. Your symptoms limit some of your daily normal activities. There is some decrease in your lung function.
• Severe persistent asthma: You have symptoms during the day and wake up every night due to asthma. You need your quick-relief medicine several times a day for asthma symptoms. Your symptoms put extreme limitations on your daily activities. There are major decreases and abnormal results in your lung function.

You may also hear about different types of asthma from your doctor or other people. These names may describe what is causing your asthma. Here are some different types of asthma:

• Allergic asthma is triggered by allergens, such as pet dander, mold, dust mites, and pollen.
• Eosinophilic [EE-oh-sin-oh-FILL-ick] asthma is caused by high levels of eosinophils in the airways. Around 50% of severe asthma is in this category.¹
• Exercise-induced bronchoconstriction (asthma) happens when the airways tighten and airflow gets obstructed (blocked) during or after exercise. It is not always clear what causes this type of asthma, but breathing in cold, dry air is a trigger.
• Cough-variant asthma is a type of asthma where the main symptom is a chronic, recurring cough. People with this type of asthma may still have other asthma symptoms like wheezing and shortness of breath, but they happen less often.
• Nighttime (nocturnal asthma) is when asthma symptoms wake you up at night, possibly due to changes in breathing patterns and/or hormones that happen while you sleep. Almost 30 to 70% of people with asthma report nighttime asthma symptoms at least once a month.²
• Occupational (work-related) asthma is caused by inhaling allergens, chemicals, and irritants in a specific work environment.