Which respiratory condition refers to an abnormally low breathing rate?

Bradypnea is the term used to describe an abnormally low breathing rate, which typically refers to a respiratory rate of less than 12 breaths per minute in adults. This condition can occur in various situations, such as drug overdose, head injury, or metabolic disturbances, and it indicates that a person's breathing is slower than normal.

Understanding the other terms can provide further context. Hypercapnia refers to an excessive amount of carbon dioxide in the bloodstream, often a result of inadequate respiration. Dyspnea is the term for difficulty breathing or shortness of breath, which is not about the rate but rather the quality of breathing. Hyperventilation is the opposite of bradypnea; it involves breathing at an abnormally rapid rate, often leading to excessive loss of carbon dioxide. Therefore, bradypnea is the appropriate term for a low breathing rate, distinguishing it from other respiratory conditions.