Asthma: Comprehensive Guide to Symptoms, Diagnosis, and Investigation

By Dr Ashish jain in Pulmonology

May 27 , 2024 | 2 min read

Asthma is a common but chronic condition that affects airways in the lungs, making it harder to breathe. It can affect anyone, but it often starts in childhood. Understanding the symptoms and how asthma is diagnosed can help manage this condition effectively. 

What is asthma?

Asthma is characterized by an inflammation and narrowing of the airways, leading to symptoms like:

  • Wheezing (a whistling sound when breathing)
  • Shortness of breath
  • Chest tightness
  • Coughing, especially at night or early morning


The symptoms range from mild to severe and these may be triggered by factors like allergens, exercise, cold air, smoke, or stress

Diagnosing Asthma 

If you experience symptoms of asthma, it's crucial to see a doctor. The diagnosis involves several steps: 

1. Medical History and Physical Exam

The doctor will ask about symptoms, their frequency, and any possible triggers.

A physical exam is conducted to check breathing and look for signs of asthma or other conditions.

2. Spirometry

This is a common lung function test. Individuals breathe into a device called a spirometer, which measures how much air is exhaled and how quickly. It helps to assess the airflow obstruction typical in asthma.

3. Peak Flow Measurement

Using a peak flow meter, doctors can measure how fast air is blown out of the lungs. This is a simple and useful tool to monitor asthma at home.

4. Bronchodilator Test

Sometimes, spirometry is done before and after using an inhaler (bronchodilator). If your lung function improves significantly after using the inhaler, it suggests that you have asthma.

5. FeNO Test

The fractional exhaled nitric oxide (FeNO) test measures nitric oxide levels in a person's breath. Higher levels of nitric oxide can indicate airway inflammation, which is common in asthma. This noninvasive test can help diagnose asthma and monitor how well treatment is working.

Additional Tests

  • Allergy Testing: Identifying allergens that trigger asthma can be helpful. Skin tests or blood tests could be conducted.
  • Methacholine Challenge Test: Methacholine is a substance that, when inhaled, can cause airway narrowing. If you react to methacholine, it suggests you have asthma.
  • Imaging Tests: Chest X-rays or CT scans may be used to rule out other conditions that can mimic asthma symptoms.

Managing Asthma

Once diagnosed, asthma can be managed with medications and lifestyle changes:

  • Inhalers: These are the main treatment for asthma. They deliver medication directly to the lungs to reduce inflammation and open airways.
  • Avoiding Triggers: Identifying and avoiding triggers like allergens or irritants, can help reduce symptoms.
  • Regular Monitoring: Using a peak flow meter at home helps monitor asthma and take action if your symptoms worsen. 


With the right diagnosis and treatment plan, asthma is manageable. If you suspect you have asthma, consult your healthcare provider for a thorough evaluation. Modern diagnostic tools like spirometry and the FeNO test play a crucial role in confirming the diagnosis and guiding treatment. With appropriate management, people with asthma can lead active, healthy lives.

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