What term describes difficult or labored breathing?

The term that describes difficult or labored breathing is dyspnea. This condition can manifest in various situations, such as during exercise, exposure to high altitudes, or in the presence of certain medical conditions like asthma, chronic obstructive pulmonary disease (COPD), or heart failure. Dyspnea is characterized by sensations of breathlessness or increased effort to breathe, which can be distressing for individuals experiencing it.

In contrast, bradypnea refers to an abnormally slow breathing rate, tachycardia signifies an elevated heart rate, and eupnea describes normal, unlabored breathing. These terms highlight different aspects of respiratory and cardiovascular function, but none specifically capture the essence of labored or difficult breathing as dyspnea does. Thus, focusing on the physiological implications of each term makes it clear why dyspnea is the correct answer in this context.