What lung function test is commonly used to assess asthma?

Spirometry is the most widely used lung function test to assess asthma because it measures how much air a person can inhale and exhale, as well as the speed of airflow during these breaths. In asthma, spirometry helps in evaluating the presence of airway obstruction and in assessing how well the lungs are functioning. The results can indicate whether there is a reversible obstruction, which is a hallmark of asthma, especially after the administration of a bronchodilator.

This test is straightforward and can be performed in a clinical setting, making it an ideal choice for diagnosing and monitoring asthma. By quantifying various aspects of lung function, such as forced expiratory volume (FEV1) and forced vital capacity (FVC), spirometry provides essential information that assists healthcare providers in making informed decisions about treatment plans and management strategies for asthma.

Other options such as bronchoscopy, a CT scan, and a chest X-ray serve different purposes and are not standard for routine evaluation of asthma. Bronchoscopy is invasive and used primarily for direct visualization of the airway; a CT scan is more useful for assessing structural abnormalities and conditions beyond asthma; and a chest X-ray can help rule out other conditions but does not provide specific data on lung function or airway responsiveness.