A respiratory rate, or breathing rate, is the number of breaths a person takes in one minute while at rest, and it can be measured by counting the number of times a person's chest rises and falls within one minute. An individual's normal respiratory rate will change based on activity levels and age; typically breathing will slow down as a person gets older, but it can increase during exercise or other strenuous exercise. The act of breathing is controlled by the brain, which tells the body to breath based on oxygen and carbon dioxide levels in the blood, and certain factors, such as exercise, drugs, and alcohol, can affect a person's breathing rate. An abnormally high or low respiratory rate may indicate certain medical conditions such as bradypnea, apnea, or tachypnea.
Changes with Age
In most cases, a person's normal respiratory rate will change with age; younger adults, children, and babies will typically have faster respiratory rates, because as people age, their breathing usually slows down. From birth to six months of age, a baby's normal breathing rate is 30 to 60 breaths per minute; after the age of six months, breathing typically slows to 24 to 30 breaths per minute. For children from the age of one to five years old, normal respiration is 20 to 30 breaths per minute, while children who are from six to twelve years old should have a normal respiratory rate that ranges from 12 to 20 breaths per minute. The normal respiratory rate for adults and children over the age of 12 usually ranges from 14 to 18 breaths per minute.
Slow Respiratory Rate
When a person's respiratory rate is slower than normal, certain conditions, such as bradypnea or apnea, may occur. Bradypnea is characterized by abnormally slow breathing, and may be the symptom of a metabolic disorder or a tumor. This condition may happen during sleep, and can be induced through the use of opiate narcotics. Apnea often occurs when a person's breathing completely stops, and can be caused by a number of conditions depending on one's age; some of the usual causes of apnea in children are asthma, bronchiolitis, gastro-esophageal reflux, seizures, or premature birth.
Adults may experience apnea due to of cardiac arrest, asthma, choking, or drug overdose. Other causes of apnea that are not as common include head injuries, arrhythmias, metabolic disorders, near-drowning incidents, strokes, and other neurological disorders. Obstructive sleep apnea, a common disorder, occurs when the airway is blocked during sleep; many treatment options exist for sleep apnea, including the use of nasal decongestants, oral appliances, or positional therapy, and surgery may be required in some cases.
Fast Respiratory Rate
The opposite of apnea is tachypnea, or rapid breathing. A faster than normal respiratory rate may be caused by the flu or a cold in children, and pneumonia and asthma may also cause an increase in the rate of respiration in people of all ages. In adults, tachypnea is usually caused by asthma, chronic obstructive pulmonary disease (COPD), chest pain, lung infections like pneumonia, or a pulmonary embolism.
A faster than normal respiration rate may also be induced by physical exercise, and many people are advised to speak to a healthcare professional before beginning any exercise programs. Rapid breathing can also happen if a person begins taking rapid deep breaths that are caused by panic or anxiety — this is called hyperventilation. The terms tachypnea and hyperventilation are often used interchangeably, although hyperventilation is characterized by deeper breathing and is usually brought on by emotional stress.