What causes pain in the left upper side of the body?

Left Upper Side Pain: Differential Diagnosis and Evaluation

Immediate Life-Threatening Causes to Exclude First

Left upper side pain requires immediate evaluation to exclude acute coronary syndrome, aortic dissection, pulmonary embolism, and pneumothorax before considering benign etiologies. 1

Cardiac Causes

• Acute coronary syndrome presents with pressure-like discomfort that builds gradually over minutes, often radiating to the left arm, jaw, or neck, and is frequently accompanied by diaphoresis, dyspnea, or nausea 1, 2
• Pain that is localized to a very limited area or sharp and stabbing is unlikely to represent myocardial ischemia 1, 2
• Fleeting pain lasting only seconds is unlikely related to ischemic heart disease, whereas anginal symptoms gradually build over minutes 2
• Women, elderly patients, and those with diabetes may present with atypical symptoms including upper abdominal pain or discomfort in the throat 1
• An immediate 12-lead ECG must be obtained in any patient with left-sided chest pain to exclude ST-segment elevation myocardial infarction, even in outpatient settings 1, 2

Aortic Dissection

• Sudden-onset "ripping" or "tearing" pain described as the "worst chest pain of my life," particularly in hypertensive patients or those with known bicuspid aortic valve or aortic dilation, is highly suspicious for acute aortic syndrome 1
• Pulse differentials between extremities occur in approximately 30% of patients with aortic dissection 1

Pulmonary Causes

• Pulmonary embolism presents with acute dyspnea combined with pleuritic chest pain, with tachycardia present in over 90% of patients 1, 2
• Pneumothorax causes dyspnea and pain on inspiration with unilateral absence of breath sounds 1, 2
• Pneumonia presents with fever, localized chest pain that may be pleuritic, and regional dullness to percussion 1

Musculoskeletal Causes (Most Common in Left-Sided Pain)

Costochondritis

• Costochondritis is the most common cause of nontraumatic musculoskeletal chest wall pain, accounting for 42% of cases 1, 3
• The hallmark finding is reproducible tenderness on palpation of the costochondral joints, typically affecting ribs 3-7, most commonly left-sided or retrosternal 3
• Pain is often described as stinging (53%) or pressing (35.1%), left-sided (69.2%), occurring more than once daily (62.9%), with chronic symptoms lasting >6 months in 55.4% of cases 1, 3
• Sharp, stabbing pain that worsens with inspiration or palpation markedly reduces the probability of cardiac ischemia 3

Other Musculoskeletal Conditions

• Positional chest pain or pain affected by palpation, breathing, turning, twisting, or bending suggests musculoskeletal etiology 2
• Tietze syndrome involves localized inflammation at one or more costochondral junctions 4
• Musculoskeletal chest wall pain may affect any chest wall structure including bones, cartilage, joints, ligaments, tendons, and muscles 1

Gastrointestinal Causes

• Upper abdominal pain or heartburn unrelated to meals may occur with myocardial ischemia, particularly in patients with diabetes, women, and elderly patients 1
• Gastroesophageal reflux disease is the most prevalent noncardiac cause of chest pain and can be effectively treated with proton-pump inhibitors 5
• Esophageal rupture may present with emesis, subcutaneous emphysema, and pneumothorax in 20% of patients 1

Other Cardiac Causes

• Pericarditis presents with fever, pleuritic chest pain that increases in the supine position, and may have a friction rub on examination 1
• Myocarditis presents with fever, chest pain, heart failure signs, and an S3 gallop 1

Critical Evaluation Algorithm

Step 1: Immediate Risk Stratification

• Obtain 12-lead ECG within 10 minutes for any patient with left upper side pain 1, 2
• Perform focused physical examination looking for diaphoresis, tachypnea, tachycardia, hypotension, pulse differentials, and unilateral breath sounds 1

Step 2: Assess Pain Characteristics

• Duration: Fleeting (seconds) = unlikely cardiac; gradual build (minutes) = consider cardiac 2
• Quality: Pressure/squeezing = cardiac; sharp/stabbing = less likely cardiac 1
• Location: Diffuse anterior chest = cardiac; highly localized = unlikely cardiac 1, 2
• Radiation: Left arm/jaw/neck = cardiac; below umbilicus = unlikely cardiac 1
• Triggers: Physical/emotional stress = angina; positional = musculoskeletal 1, 2

Step 3: Associated Symptoms

• Presence of diaphoresis, dyspnea, nausea, or syncope increases likelihood of acute coronary syndrome 1, 2
• Absence of these symptoms significantly reduces likelihood but does not exclude cardiac causes 2

Step 4: Physical Examination Findings

• Reproducible tenderness on palpation of costochondral joints = costochondritis 3
• Friction rub = pericarditis 1
• Unilateral absent breath sounds = pneumothorax 1
• Pulse differential = aortic dissection 1

Step 5: Diagnostic Testing Based on Risk

• High risk (abnormal ECG, hemodynamic instability, clinical evidence of ACS): Immediate transfer to emergency department by EMS 2
• Intermediate risk: Serial ECGs, cardiac biomarkers, consider stress testing or coronary CT angiography 1
• Low risk with clear musculoskeletal findings: Conservative management with NSAIDs for 1-2 weeks 3

Important Pitfalls to Avoid

• Do not use nitroglycerin response as a diagnostic criterion, as relief with nitroglycerin does not distinguish cardiac from non-cardiac chest pain 1, 3
• Do not assume all reproducible chest wall tenderness is benign, as serious cardiac conditions can coexist with musculoskeletal findings 3
• Do not delay cardiac evaluation in high-risk patients (age >75 years, diabetes, renal insufficiency, known coronary artery disease) even if pain seems musculoskeletal 2
• Do not miss atypical presentations in women, elderly patients, and those with diabetes who may have upper abdominal pain or throat discomfort as their primary symptom 1

Management Based on Etiology

If Cardiac Cause Suspected

• Immediate aspirin 75-500 mg, glyceryl trinitrate, and oxygen if required 2
• Urgent transfer to emergency department for further evaluation and potential revascularization 2

If Costochondritis Confirmed

• NSAIDs for 1-2 weeks as first-line treatment 3
• Low-dose colchicine may be added if symptoms persist despite NSAID therapy 3
• Topical analgesics (lidocaine patches) for localized pain relief 3
• Ice or heat application as adjunctive non-pharmacological measure 3

If Other Non-Cardiac Cause

• Chest radiograph is useful to evaluate for pulmonary and thoracic causes of symptoms 1
• Treatment directed at specific underlying condition identified 1