Asthma: tests and stages of diagnosis

The diagnosis of asthma usually requires a medical history, physical examination and lung tests.

The diagnosis of asthma is based on several factors, including a detailed medical history, a physical examination, your symptoms, your general health and test results.

Medical history

The first step in diagnosing asthma is to discuss your symptoms and health status with your doctor. This may give you a clue as to whether your symptoms are caused by asthma or something else. Your doctor may ask you about your symptoms and your exposure to asthma-associated substances. These questions may include.

What are your symptoms, when do they occur, and what triggers them, if anything?

Are you regularly exposed to tobacco smoke, chemical fumes, dust or other irritants in the air?

Do you have hay fever or any other allergic disease?

Do you have any blood relatives, such as parents, aunts, uncles, grandparents or cousins, who suffer from asthma, hay fever or other allergies?

What health problems do you have?

What medications or herbal supplements do you take?

What do you do at work?

Do you have pets, or do you own pigeons?

Physical exam

Your doctor may.

Check your nose, throat, and upper airway.

Listen to your breathing with a stethoscope. Shortness of breath and a high-pitched wheezing sound when you exhale is one of the main signs of asthma.

Check your skin for signs of allergies, such as eczema or hives.

Your doctor will want to know if you have any of the usual signs and symptoms of asthma, for example.

Recurrent wheezing

coughing

Breathing problems

Chest discomfort

Symptoms that appear or increase at night

Symptoms triggered by cold air, exercise, or allergen exposure

Signs and symptoms of asthma in children

There are other signs and symptoms that may indicate the presence of asthma in children. They may include the following.

Breathing that is louder or faster than usual.

Frequent coughing or coughing that gets worse after active play.

Cough, clear mucus and runny nose due to hay fever.

Absence from school for several days

Limited participation in physical activities

Testing or studying

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Your doctor may use several tests to determine how well your lungs are working.

Spirometry

This is the main test doctors usually use to diagnose asthma in people age 5 and older.

To find out how well your lungs are working (lung function), you breathe in deeply and exhale forcefully into a tube connected to a spirometer. It records both the amount of air you exhale (volume) and the rate of exhalation. If some of the readings are lower than normal for someone your age, this may indicate that asthma has constricted your airways.

After the lung test, your doctor may ask you to inhale your asthma medication to open your airways and retest. If you get significant improvement after taking the medicine, this may mean you have asthma.

Stimulation test

If your spirometer results are normal or near normal, your doctor may try to induce asthma symptoms by asking you to inhale a substance that narrows the airways of people with asthma, such as methadone.

If your asthma seems to be triggered by exercise (exertional asthma), you may be asked to exercise to see if this triggers your symptoms.

You should repeat the spirometry test after each activity. If your spirometry readings are normal, you probably do not have asthma. However, if your readings are significantly lower, you may have asthma.

Lung tests and screening for children

Doctors rarely test the lungs of children under the age of five. Instead, diagnosis is usually based on the child's signs and symptoms, medical history and physical examination. Diagnosing asthma in young children is especially difficult because there are many conditions that cause asthma-like symptoms at this age.

If your child's doctor suspects asthma, he or she may prescribe a bronchodilator, a medication that opens the airways. If your child's signs and symptoms improve after using a bronchodilator, he or she may have asthma.

Exhaled air nitric oxide testing

Breathe into a tube connected to a machine that measures the amount of nitric oxide in your breath. Your body normally produces nitric oxide, but an elevated level of nitric oxide in your breath could mean that your airways are inflamed, which is a sign of asthma.

Other tests: how to rule out diseases other than asthma

If your doctor suspects that you have a condition other than asthma or another medical condition, you may need the following tests

A computer-based tomography (CT) scan or also a chest x-ray or CT scan of the sinuses.

Blood tests.

Evaluation of gastroesophageal reflux disease.

Sputum examination of the lungs (injection and examination of the sputum) to look for signs of viral or bacterial infection.

Your physician may also want to check for other conditions that often accompany asthma and may worsen symptoms. These include the following.

Heartburn (also known as GERD or gastroesophageal reflux disease).

Hay fever

Sinusitis.

Your doctor may also do an allergy test. This may be a skin test, a blood test, or both. Although allergy tests are not used to diagnose asthma, they can help identify allergic conditions that may be causing symptoms or worsening existing asthma, such as hay fever.

Sometimes it can be difficult to diagnose the cause of a breathing problem. Differentiating asthma from other conditions can be difficult, especially in young children.

If asthma occurs at the same time as other diseases that affect breathing, it can make diagnosis even more difficult.

Even if a diagnosis is not made, the doctor may prescribe medications or other treatments to see what helps. It can take time and patience to make an accurate diagnosis and determine the best treatment.

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