There are several common causes of shallow breathing, according to the U.S. National Library of Medicine, including asthma, blood clot, and choking. COPD, heart failure, lung infection, pneumonia or transient tachypnea can also cause rapid, shallow breathing.
A normal and healthy resting adult should take between eight and 16 breaths every minute. Shallow breathing may or may not cause a change in the number of breaths taken, but those breaths would not adequately supply the oxygen needed to the body. The person suffering with shallow breathing may begin to feel lightheaded.
Doctors suggest seeking immediate medical attention if the person with shallow breathing suffers additional symptoms, such as change in skin color, chest pains, or fever.
WebMD lists detailed information on breathing problems in its lung disease and respiratory health center section.