Eupnea is the medical term for normal, quiet, and unlabored breathing. It represents the body’s natural state of respiration when in a relaxed condition. It is the default, efficient pattern that ensures a balance between taking in air and minimizing the work of respiratory muscles.
Characteristics of Normal Breathing
During this form of breathing, known as quiet breathing, the primary muscles involved are the diaphragm and the external intercostal muscles. A key indicator of eupnea is the respiratory rate, which is the number of breaths taken per minute. For healthy adults at rest, a normal rate falls between 12 and 20 breaths per minute.
This rate is faster in children and varies by age; infants may have a rate of 30-60 breaths per minute, while school-aged children might be between 18 and 30. A teenager’s resting respiratory rate aligns with an adult’s.
How the Body Regulates Breathing
Breathing is automatically regulated by the nervous system. This control originates in the respiratory centers located within the brainstem, specifically in the medulla oblongata and the pons. These centers work without conscious input to maintain a steady breathing rhythm, ensuring the body receives the oxygen it needs while expelling carbon dioxide.
The medulla oblongata sets the basic pace and depth of breathing. It sends signals to the diaphragm and intercostal muscles, prompting them to contract for inhalation. When these signals cease, the muscles relax, and exhalation occurs passively. This system constantly adjusts to information from chemoreceptors that monitor oxygen and carbon dioxide levels in the blood, modifying the breathing rate to maintain balance.
Recognizing Abnormal Breathing
Deviations from the normal rate, rhythm, and effort can indicate an underlying issue. Common examples include tachypnea, which is characterized by abnormally rapid and shallow breathing, often defined as more than 20 breaths per minute in a resting adult. Another deviation is bradypnea, or an abnormally slow breathing rate of fewer than 12 breaths per minute in an adult.
The term dyspnea describes the subjective feeling of difficult or labored breathing, commonly known as shortness of breath. If you have concerns about your breathing, it is best to consult with a healthcare professional for an evaluation.