How is Asthma Diagnosed?

To diagnose asthma, your doctor will use tests. Some measure how well your lungs work. Other people can determine if you are allergic to mold or pollen.

These asthma tests will help your doctor determine if you have asthma.

Physical Examination of asthma

Your doctor will begin with a physical examination. They will:

  • Take a look at your throat, nose, and upper airways.
  • When you inhale, use a stethoscope and listen for a whistling sound.
  • Check your skin to see if you have allergies, such as eczema or hives.

They will also ask about signs and symptoms of asthma, such as:

  • Wheezing
  • Cough
  • Breathing problems
  • Chest tightness

Medical History

Your doctor will then ask you about your symptoms and general health to determine if asthma is the cause of your problem. Some questions might include:

  • Which symptoms are you experiencing?
  • What time do you need them?
  • What might trigger them? How about exercise, cold air, or allergies?
  • Are you suffering from hay fever?
  • Is hay fever, asthma, or allergy a common condition in the family?
  • Which other health issues do you have?
  • What medicines are you taking?
  • Are you exposed to tobacco smoke, dust, pets, or other chemicals in the air?
  • What are you doing for a living?

Lung Function Tests

Lung function tests can be used to test how your lungs work. Doctors use them to diagnose and monitor the progression of asthma. Because you might not determine if your asthma is under control from just your symptoms, watching it with lung function tests can help.

Lung function tests are performed in an exam room equipped with special devices that measure lung function. The tests are usually performed by a specially trained technician or respiratory therapist.

Discuss what you can do to prepare for your lung function test with your doctor. However you might have to change your medication. Avoid heavy meals, smoking, or any other substance that could trigger an asthma attack.

How is Asthma Diagnosed |

Types and results of lung function tests

These tests of lung function are used frequently to diagnose and monitor asthma.

  • The most popular is Spirotometry. This is a quick and painless method to test your lungs. Take a deep inhale and exhale into the hose attached to a device known as a spirometer. However the spirometer records the amount of air you exhale (called forced vital capability or FVC) as well as how fast you do it (called forced exhaustion volume or FEV). Your score will be lower if your airways are constricted or swollen due to asthma or other lung diseases. Your doctor might order you to have multiple spirometry lung function tests to monitor your asthma. To determine if medication is helping, you might have spirometry before or after taking medicine. Your doctor might also request readings to determine how exercise affects your airways.
  • A Challenge test is a lung function test that helps confirm asthma diagnosis. Inhale a small amount of histamine or methacholine. This substance is known to cause asthma symptoms. Someone will test your lung function after you inhale the substance. It would help if you only had experience with these tests, as they can trigger asthma attacks.
  • Peak flow meters test how efficiently your lungs produce air. These lung function tests are not as accurate as spirometry but can try your lung function at home. You can use peak flow meters to determine if your asthma is getting worse and if you need emergency medical care. However a peak flow meter is a small, handheld plastic tube that you can breathe into. It has a mouthpiece at one end. Your doctor might ask you to use the peak flow monitor every day and record the readings. You should report the results to your doctor after a few weeks.
  • Inhaled nitric dioxide test. A tube will be attached to a machine that measures nitric oxygen levels in your lungs.The body produces this gas naturally, but it can be elevated if your airways become inflamed.

Additional tests you may need if you have asthma.

Your doctor may order additional tests, even if your tests for lung function are regular. This could help to determine what is causing your asthma symptoms.

  • Gas and diffusion test are tools that can be used to measure the amount of oxygen in your blood and other gases in the air. Inhale a small amount of the gas and hold your breath. Then, exhale. To determine how much gas your blood has absorbed, the amount of gas you exhale will be analyzed.
  • X-rays can tell you if your lungs are in good shape or if your symptoms may be caused by asthma. High-energy radiation takes a picture of the inside of your lungs. While examining the X-ray machine, you might be asked to hold your breath for a moment.


Sinusitis and nasal polyps can make asthma more difficult to manage. The term sinusitis also refers to inflammation of the sinuses caused by infection. The sinuses can become blocked and clogged with fluid. This can lead to infection and inflammation. If you suspect a sinus infection, your doctor might order a CT scanner to check your sinuses. Antibiotics cure Sinusitis. However this treatment should last between 10 and 12 days. Sinusitis treatment may help to prevent symptoms of asthma.

Tests for other conditions

Other conditions that could worsen asthma include:

  • Gastroesophageal Reflux Disease ( GERD).
  • Allergies

Assessing the severity of asthma

Your doctor will likely diagnose you with asthma based on your symptoms and the results of these tests. Next, determine if you have severe asthma. However This will allow them to determine the best treatment. These are the four types of asthma you will have:

  1. Mild intermittent asthma. Mild symptoms less often than once a week. Nighttime symptoms are less frequent than once a month. Few asthma attacks.
  2. Mild persistent asthma. Symptoms 3 to 6 times per week. Nighttime symptoms are usually three to four times per month. Asthma attacks might affect activities.
  3. Persistent moderate asthma. Symptoms every other day. Five or more nights per month with nighttime symptoms. Asthma attacks can affect your daily activities.
  4. Persistent severe asthma. You experience persistent symptoms day and night. These symptoms are so common that you need to limit your activities.

A doctor can prescribe medication to manage your asthma and prevent attacks if diagnosed with it.