What describes a state of hypoventilation?

Hypoventilation refers to a decrease in the rate and/or depth of breathing, leading to insufficient ventilation that does not meet the body’s needs for oxygen intake and carbon dioxide removal. Choosing "breathing that is too slow" accurately describes hypoventilation because it indicates that the person is not breathing adequately to maintain normal gas exchange in the lungs.

In hypoventilation, the slower breathing rate can result in an increase in carbon dioxide levels in the blood, leading to respiratory acidosis and potentially decreasing oxygen levels. This scenario typically occurs due to various reasons, including respiratory diseases, sedative use, or conditions affecting the muscles responsible for breathing.

The other choices represent conditions that are contrary to the physiological state of hypoventilation. Normal energy expenditure would imply a balanced respiratory rate, very deep breaths would suggest hyperventilation or increased ventilation instead of decreased, and rapid and excessive breathing describes hyperventilation, which is the opposite of hypoventilation. Thus, the definition that correctly fits the concept of hypoventilation is breathing that is too slow.