What Is a Normal Respiration Rate, and What Controls Breathing?

Every time you breathe in and out, your lungs inhale oxygen-rich air and exhale carbon dioxide, a waste gas. The number of breaths you take in one minute is known as your respiration rate, or breathing rate, according to Johns Hopkins Medicine.

"The rate is usually measured when a person is at rest and simply involves counting the number of breaths for one minute by counting how many times the chest rises," they explain. Healthcare providers often use a stethoscope to listen to the quality of a patient's lungs and breathing.

Infants, with their tiny lungs, have to breathe rapidly to bring in enough oxygen; they take 30 to 60 breaths per minute, according to a handbook published by the University of Iowa Stead Family Children's Hospital.

As children grow, their lungs mature and they're able to exchange more air with each breath. The normal human respiratory rate drops gradually until age 12, when it levels off, according to the U.S. National Library of Medicine (NLM).

As noted by the University of Iowa, toddlers breathe 24 to 40 times a minute at rest. A good respiratory rate for preschoolers is 22 to 34, and school-aged children breathe 18 to 30 times a minute on average. For adolescents aged 12 years and up, a respiration rate of 12 to 16 breaths per minute is considered good.

Respiration rates for healthy adults at rest range from 12 to 16 breaths per minute, according to Johns Hopkins.

However, your respiration rate can be significantly affected by illness, fever and medical conditions. Difficulty breathing and respiration rates outside the normal range for children or adults are signals that it's time to seek medical attention.

Respiration rate, blood pressure, pulse rate and body temperature are known as the four vital signs that give your healthcare providers a quick snapshot of your overall health, per the NLM.

To help adjust your breathing rate to changing chemical needs, your body has sensors that send signals to the respiratory centers in the brain, according to the National Heart, Lung and Blood Institute (NHLBI). These neural mechanisms then activate your respiratory muscles accordingly.

The primary respiratory muscle is the diaphragm, as explained by experts at the Cleveland Clinic. "When you breathe in, your diaphragm contracts and flattens, moving down towards your abdomen," they write. "This movement creates a vacuum in your chest, allowing your chest to expand and pull in air. When you breathe out, your diaphragm relaxes and curves back up as your lungs push the air out."

The diaphragm's movement is controlled by the phrenic nerve, which according to materials published by the National Center for Biotechnology Information originates at the top of your spine and traverses your neck, heart and lungs before ending at your diaphragm muscle.

The breathing pattern that is essential to life is all about the concentration of oxygen and carbon dioxide in the blood. Put simply, "Your brain controls your breathing rate by sensing your body's need for oxygen and its need to get rid of carbon dioxide," writes the NHLBI. "Your breathing usually does not require any thought, because it is controlled by the autonomic nervous system, also called the involuntary nervous system."

Chemoreceptors in the brain and the arteries "monitor" the amount of oxygen and carbon dioxide present in the body. If the balance of any of these chemicals is disrupted, they modulate the respiratory rate to compensate. Too much carbon dioxide and too little oxygen in the blood prompts the respiratory rate to increase; too little carbon dioxide and too much oxygen cause it to decrease.

Even today, it is still not understood exactly how the brain controls respiration. "Breathing is a more complex behavior than the heartbeat," explains an article published by the University of California, San Francisco. "It can be voluntary or involuntary; it must be coordinated with speech, singing and swallowing; and it has distinct variations, like sighs, yawns and gasps, which can be tied to a range of emotions."

In 1991, it was discovered that respiration is regulated by a group of thousands of cells in the brain stem, a cluster known as the preBötzinger Complex. But the mechanism by which this cell cluster regulates breathing is still being studied.