Shallow breathing, thoracic breathing, costal breathing or chest breathing^[1] is the drawing of minimal breath into the lungs, usually by drawing air into the chest area using the intercostal muscles rather than throughout the lungs via the diaphragm. Shallow breathing can result in or be symptomatic of rapid breathing and hypoventilation. Most people who breathe shallowly do it throughout the day and they are almost always unaware of the condition.

In upper lobar breathing, clavicular breathing, or clavicle breathing, air is drawn predominantly into the chest by the raising of the shoulders and collarbone (clavicles), and simultaneous contracting of the abdomen during inhalation.^[2] A maximum amount of air can be drawn this way only for short periods of time, since it requires persistent effort.

Conditions

Several conditions are marked by, or are symptomatic of, shallow breathing. The more common of these conditions include: various anxiety disorders, asthma, hyperventilation, pneumonia, pulmonary edema, and shock. Anxiety, stress, and panic attacks often accompany shallow breathing.^{[citation needed]}

Overly shallow breathing, also known medically as hypopnea, may result in hypoventilation, which is a serious condition if of ignored or not properly diagnosed. It is often treated as a "sleep disorder" without adequate diagnostic information.^{[citation needed]} Serious symptoms arise most commonly during sleep, when the intercostal muscles do not perform the breathing action. During sleep, breathing originates from the diaphragm, which is often impaired in people with NMDs.^{[citation needed]}

Polio survivors with breathing conditions and others with NMDs may be given a tracheostomy (a surgical opening for breathing made in the neck).^{[citation needed]}