What causes asthma symptoms to occur?

Asthma symptoms occur primarily due to a spasm of the muscle lining in the bronchi, which leads to narrowing of the airways. This bronchoconstriction can be triggered by various factors, including allergens, exercise, cold air, or respiratory infections. When the muscles around the airways contract, this causes the air passages to become tighter and inflamed, making it difficult for air to flow in and out of the lungs, leading to symptoms such as wheezing, shortness of breath, coughing, and chest tightness.

While inflammation of lung tissue can contribute to the overall respiratory issues in individuals with asthma, it is the acute spasm of the bronchi that directly triggers the sudden asthma symptoms. In contrast, obstruction in the esophagus is not related to asthma, and pneumothorax, which involves air leaking into the pleural space surrounding the lungs, is a separate condition that can lead to respiratory distress but is also not a cause of asthma symptoms.