Intercostal retractions occur when the muscles between the ribs pull inward. The movement is most often a sign that the person has a breathing problem.
Intercostal retractions are a medical emergency.
Retractions of the chest muscles
The wall of your chest is flexible. This helps you breathe normally. Stiff tissue called cartilage attaches your ribs to the breast bone (sternum).
The intercostal muscles are the muscles between the ribs. During breathing, these muscles normally tighten and pull the rib cage up. Your chest expands and the lungs fill with air.
Intercostal retractions are due to reduced air pressure inside your chest. This can happen if the upper airway (trachea) or small airways of the lungs (bronchioles) become partially blocked. As a result, the intercostal muscles are sucked inward, between the ribs, when you breathe. This is a sign of airway obstruction. Any diseases or condition that causes a blockage in the airway will cause intercostal retractions.
Watts KD, Goodman DM. Wheezing, bronchiolitis, and bronchitis. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 383.
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.