Which of the following is defined as labored breathing?

The term that describes labored breathing is dyspnea. Dyspnea refers to the sensation of difficulty or discomfort in breathing, which can manifest as shortness of breath or an increased effort required to breathe. This condition can be a symptom of various medical issues, including respiratory infections, heart conditions, or allergies, and can range from mild to severe.

Apnea denotes a temporary cessation of breathing, which is distinct from labored breathing since it refers to a complete halt rather than difficulty. Tachypnea is characterized by rapid breathing, while bradypnea is the term for abnormally slow breathing. Both tachypnea and bradypnea involve changes in the rate of breathing rather than the effort involved, which differentiates them from dyspnea. Thus, dyspnea correctly identifies the sensation of labored breathing.