Gastroesophageal Reflux Disease (GERD): This is often the most common cause of chest pain, especially if the pain is described as a burning sensation that may radiate to the neck or arms, and is typically exacerbated by lying down or heavy meals.

Musculoskeletal Pain: Strains or inflammation of the muscles and joints in the chest wall can cause sharp pains that are usually localized and worsened by movement or deep breathing.
Anxiety or Panic Disorder: These conditions can manifest as chest pain or discomfort, often accompanied by other symptoms like palpitations, shortness of breath, or fear of dying.
Pulmonary Embolism: While not as common as other causes, pulmonary embolism should be considered, especially in patients with risk factors like recent surgery, immobilization, or known thrombophilic conditions.
Asthma or Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: These conditions can cause chest tightness or pain, especially if associated with wheezing, cough, or shortness of breath.

Myocardial Infarction (MI): Although not the most common cause, MI is a critical diagnosis to consider due to its high morbidity and mortality. It typically presents with a squeezing or pressure-like pain that may radiate to the arm, neck, or jaw, and is often accompanied by diaphoresis, nausea, or shortness of breath.
Aortic Dissection: A life-threatening condition where there is a tear in the aorta's inner layer, causing severe, tearing chest pain that may radiate to the back.
Pneumothorax: Air in the pleural space can cause sudden, sharp chest pain and shortness of breath, which can be life-threatening if not promptly treated.
Esophageal Rupture: A rare but dangerous condition where the esophagus tears, often due to severe vomiting or an instrument like an endoscope, leading to severe chest pain and potentially life-threatening complications.

Pericarditis: Inflammation of the pericardium, the sac surrounding the heart, can cause sharp, stabbing chest pain that may improve with leaning forward.
Pulmonary Artery Hypertension: Elevated blood pressure in the pulmonary arteries can lead to chest pain, among other symptoms, due to right heart strain.
Costochondritis (Tietze's Syndrome): Inflammation of the cartilages that connect the ribs to the sternum, causing localized pain and tenderness.
Mitral Valve Prolapse: A condition where the mitral valve does not close properly, which can lead to chest pain among other symptoms, though it is more commonly associated with palpitations and murmurs.