tachypnea

Tachypnea simply means breathing faster than normal — too many breaths per minute. Think of it as the body's way of turning up the ventilation dial: when something is wrong, one quick fix is to move air in and out more often.

In a resting adult, a normal rate is roughly twelve to twenty breaths a minute; counting consistently above this, especially above twenty-four, is usually called tachypnea, though normal ranges are higher in children and infants. Importantly, tachypnea describes only the rate, not the depth or effort, and it can occur with shallow breaths just as easily as with deep ones.

The body speeds up breathing to blow off excess carbon dioxide, to compensate for an acidic blood chemistry, to grab more oxygen when the lungs are diseased, or simply because of fever, pain, anxiety or exertion. In a sick patient, a rising respiratory rate is one of the earliest and most sensitive warning signs of deterioration — often shifting before blood pressure or pulse — yet it is frequently the vital sign most easily overlooked.

Tachypnea should be distinguished from hyperventilation, which means breathing more than the body's carbon dioxide production requires; a person can be tachypneic with shallow breaths and still not be hyperventilating, and vice versa.