What is the pathophysiology of chest pain?

Coronary occlusions: There are multiple causes of chest pain, the most common and ominous being coronary artery occlusions with atherosclerosis.

Depends on the cause: Chest pain can be a symptom of heart disease but may be may other things such as esophageal spasms, great vessel disease, respiratory disorders (asthma, COPD, bronchitis, infections), and muscle problems to name a few. It really depends on the clinical situation and other symptoms you may be having.