Definition
Chest tightness in the context of anxiety is a sensation of pressure, squeezing, or constriction across the chest wall, produced by the body's stress response rather than by cardiac disease. New chest pain always warrants medical evaluation. Recurrent chest tightness with a normal cardiac workup is most often the chest wall and breathing pattern, not the heart.
What it can feel like
A weight on the sternum. A band around the ribs. Difficulty taking a full breath. People often place a flat hand over the center of the chest when they describe it. The sensation can outlast the conscious anxiety that triggered it, sometimes lingering for hours.
Why it happens
Adrenaline and shallow breathing tighten the intercostal muscles between the ribs, the diaphragm, and the small accessory muscles near the collarbone. Held muscles ache. Held breathing changes blood chemistry within minutes. The combination produces the pressure-and-squeezing quality. Slow exhalation, gentle movement, and treatment of the underlying anxiety pattern tend to help. A longer plain-language walkthrough is in the article on chest tightness from anxiety.
When to see a clinician
A first episode of unexplained chest pain or pressure should be evaluated medically, even when anxiety seems like the obvious explanation. After cardiac causes have been ruled out, recurring anxiety-driven chest tightness is best treated by addressing the underlying anxiety.