What is a defining characteristic of asthma?

The defining characteristic of asthma is difficulty in breathing. Asthma is a chronic lung condition that leads to inflammation and narrowing of the airways, which can cause wheezing, shortness of breath, chest tightness, and coughing. These symptoms arise because the muscles around the airways tighten, and excess mucus production can block airflow, making it challenging for individuals to breathe easily, particularly during physical activity or at night.

Other choices, while they might relate to different health conditions, do not define asthma. Severe joint pain can be indicative of conditions like arthritis; high blood pressure is often associated with cardiovascular diseases, and loss of coordination could suggest neurological disorders or musculoskeletal issues. However, none of these manifestations are central to the diagnosis or understanding of asthma itself.