Acute Coronary Syndrome (ACS): This is often the first consideration for chest pain due to its high prevalence and potential for severe outcomes. Justification: ACS, including myocardial infarction, is a leading cause of morbidity and mortality and presents with chest pain as a primary symptom.

Gastroesophageal Reflux Disease (GERD): Chest pain can be a symptom of GERD, especially if it worsens with eating or lying down. Justification: GERD is common and can cause chest discomfort or pain that may mimic cardiac issues.
Musculoskeletal Pain: Strains or inflammation in the chest wall muscles can cause pain. Justification: This is a common and often benign cause of chest pain, especially if the pain is reproducible with movement or palpation.
Pulmonary Embolism (PE): While less common than ACS, PE is a significant cause of chest pain, especially in patients with risk factors for thromboembolism. Justification: PE can present with sudden onset chest pain and is critical to diagnose early due to its high mortality rate if untreated.
Pneumonia or Pleuritis: Infections or inflammation of the lung tissue or pleura can cause chest pain. Justification: These conditions can cause sharp, stabbing pain that worsens with deep breathing or coughing.

Aortic Dissection: A life-threatening condition where the inner layer of the aorta tears. Justification: Although rare, aortic dissection has a high mortality rate if not promptly diagnosed and treated, making it crucial not to miss.
Pulmonary Embolism (also listed under Other Likely Diagnoses): Due to its potential for high mortality, it's essential to consider PE in any patient with chest pain, even if other diagnoses seem more likely.
Esophageal Rupture: A rare but potentially fatal condition that can cause severe chest pain. Justification: Early diagnosis is critical for survival, making it a "do not miss" diagnosis.
Cardiac Tamponade: Fluid accumulation in the pericardial sac that can compress the heart. Justification: This condition can lead to shock and death if not promptly treated, emphasizing the need for early recognition.

Pericarditis: Inflammation of the pericardium, which can cause chest pain. Justification: While not as common as other causes, pericarditis can be a significant cause of chest pain, especially if accompanied by a pericardial friction rub.
Mitral Valve Prolapse: A condition where the mitral valve does not close properly, which can cause chest pain among other symptoms. Justification: This is a less common cause of chest pain but should be considered, especially in younger patients or those with a history of valvular disease.
Spontaneous Pneumothorax: Air in the pleural space without trauma, which can cause sudden chest pain. Justification: Although rare, spontaneous pneumothorax is a medical emergency requiring prompt intervention.