Asthma Diagnosis

Diagnosing asthma is a fairly straightforward process for a doctor, who uses a combination of history, symptoms and testing to decide if a person with breathing problems has asthma.

The doctor’s approach will consist of the following activities:

1. A detailed medical history, including a family health history
2. A physical exam that focuses on the upper respiratory tract, chest, and skin
3. Testing to see if the breathing problems might be reversible

By using this approach, the doctor is trying to establish whether there are episodes where airflow is at least partially obstructed, whether this airflow obstruction is reversible, and whether there could be any other reason for the breathing problems.

When your doctor is trying to make a diagnosis of asthma, he will be looking for some key factors. According to the National Institutes of Health’s Guidelines for the Diagnosis and Management of Asthma, these factors don’t prove asthma is present, but when several are present, it is likely that asthma is the problem.

Learn more about:

• Knowing Your Family Health History
• Tips for Keeping a Medical History

Getting Your Medical History

The doctor's first step in making a diagnosis of asthma is to find out as much as possible about your health history and your family's health history. This information can help identify your current health condition, as well as certain risk factors that make it more likely you will develop asthma.

First, Identify Your Symptoms

The more you can tell your doctor about the symptoms you or your child are having, the easier it will be for him or her to diagnose the breathing problems. If you can, keep a record of the types of symptoms, when they occur, and any patterns.

Do You Have Wheezing? With wheezing, high-pitched whistling sounds are heard on the exhaled breath. Not everyone with asthma has wheezing, but it is common in children.

Do You Have Any of These Other Symptoms?

• Cough, which is worse at night
• Frequent wheezing
• Frequent shortness of breath
• Frequent chest tightness

Do Symptoms Get So Bad During the Night That They Awaken You? Waking up during the night with coughing that won't quit, wheezing, and even trouble breathing are some common signs of untreated (or poorly controlled) asthma.

Learn more about:

• Understanding Asthma Symptoms
• What Is Wheezing
• The Sounds of Asthmatic Breathing
• Chronic Cough & Asthma

Then, Pinpoint What Triggers Your Symptoms

Triggers are substances or situations that tend to set off your asthma symptoms when you come into contact with them. Your body, for unknown reasons, perceives these things as threats to your health. In response, your immune system initiates the inflammatory response and causes the symptoms described above. This combination of asthma-like symptoms in response to common asthma triggers will help your doctor with diagnosing asthma.

Here are some common asthma triggers that can cause symptoms to start or worsen:

• Exercise
• Viral infection
• Animals with either fur or feathers
• House dust mites (found in mattresses, overstuffed furniture, carpets, pillows)
• Mold, either outdoors or indoors
• Tobacco or wood smoke
• Pollen from grass, trees, or weeds
• Changes in weather, especially cold weather
• Strong laughing or crying or emotional stress
• Chemical fumes or dusts
• Menses

Learn more about:

• What Sets Off Your Asthma Symptoms?
• Indoor Triggers
• Outdoor Triggers
• Job Related Triggers

Next, Share Your Family Medical History

Asthma and allergies do tend to run in families. So, if you have a parent or sibling who have either nasal allergies or asthma, you have a higher potential for getting asthma yourself.

So, your doctor will want to know who else in your family has been diagnosed with asthma or allergies in the past.

Performing a Physical Exam

Next, your doctor will examine your upper respiratory system and perform some tests. These tests help a picture of how well your lungs' performance and to predict your future as far as breathing problems.

Here are some physical findings that will suggest to your doctor that you may have a diagnosis of asthma:

• Hyperexpansion of the thorax or chest cavity: This finding is especially crucial in children. The doctor will be looking for use of accessory muscles in the hollows between the ribs to aid breathing, hunched shoulders, and chest deformity.


• Wheezing on the exhale and/or difficulty breathing out: Both of these symptoms mean you have some kind of airway blockage from inflammation or mucus.


• Increased nasal inflammation: extra mucus, swelling of the tissues inside your nostrils and nose, and nasal polyps.


• Evidence of other allergic conditions: The doctor will specifically be looking for signs of eczema or other skin rashes.

Lung Testing

Next, the doctor will want to test how well your lungs are functioning. These main types of tests are used:

• Peak expiratory flow
• Spirometry
• Methacholine challenge

A peak flow meter is a handheld device that measures how well your lungs are working when you exhale.

Spirometry also measures how well you can empty your lungs when exhaling. To diagnose asthma, doctors will usually do spirometry both before and after you use a short-acting bronchodilator. Spirometry is hard to do with young children because they can't use the equipment easily.

Methacholine challenge testing can be used when symptoms and spirometry results do not provide enough evidence to make a diagnosis of asthma. It is used more in adults than in children.

Learn more about:

• The Role of Peak Flow Meters in Diagnosing Asthma
• Other Common Peak Flow Meter Questions
• Pulmonary Function Testing

If the doctor makes an asthma diagnosis, the next step is to classify the level of asthma. This helps the doctor decide how to treat you or your child. The table below outlines the main factors used to classify asthma: