What condition is characterized by muscle spasms in the air passages?

The condition that is characterized by muscle spasms in the air passages is asthma. Asthma is a chronic respiratory condition where the airways become inflamed and narrowed, leading to muscle spasms, which can result in difficulty breathing, wheezing, and coughing. These muscle spasms occur as a response to various triggers, such as allergens, exercise, or irritants, causing a temporary obstruction in airflow.

In contrast, pneumonia is an infection that inflames the air sacs in one or both lungs, filling them with fluid or pus, leading to cough with phlegm, fever, and difficulty breathing, but does not primarily involve muscle spasms. Bronchitis, while it does involve inflammation of the bronchial tubes, is commonly characterized by a persistent cough and mucus production rather than spasms. Respiratory failure refers to a severe condition in which the respiratory system fails in oxygenating blood or eliminating carbon dioxide, but it is not specifically related to muscle spasms in the airways. Thus, asthma is distinct in its association with bronchospasm and is identified as the correct condition in this context.