What characterizes severe asthma?

Severe asthma is characterized by significant chest indrawing, which indicates a more serious level of respiratory distress. This symptom occurs when the muscles between the ribs pull in during inhalation, as the body strives to compensate for the inadequate airflow caused by narrowed airways. In severe cases, patients may also show signs of increased work of breathing and can exhibit accessory muscle use.

The other choices do not reflect the severity of the condition. For instance, the ability to speak in sentences typically suggests that a patient is not in severe distress, as they can manage their breathing adequately. Similarly, a quiet wheeze with shortness of breath could indicate that an individual is not experiencing an acute exacerbation, and the ability to move freely without distress suggests that the patient's asthma is well-controlled and not severe. Thus, significant chest indrawing is a definitive sign pointing towards severe asthma, highlighting the urgency of the situation.