Chest pain is one of the highest-stakes presentations in medicine. Most causes are benign, but a handful can kill within hours — so the safe approach is to work the differential in reverse: exclude the life-threatening causes first, then reason toward the common benign ones. This is a clinician's reference, not a protocol; actual investigation and management should follow your local or national pathway.
A principle that runs through the literature: treat anyone with chest pain as being at high cardiovascular risk until the dangerous causes are excluded, and consider a cardiac cause unless another is clearly apparent. History and examination alone are frequently insufficient to confirm or exclude acute coronary syndrome, and patients with an ischaemic cause can look deceptively well (American Family Physician).
Why a structured approach matters
The danger in chest pain is premature closure — latching onto a plausible benign explanation ("it's just reflux") before the catastrophic causes are off the table. A disciplined sequence — rule out the killers, then run a by-system differential, then risk-stratify with objective tests — guards against that. It also produces a defensible record of your reasoning.
Step 1 — exclude the life-threatening causes
Before anything else, consider the "can't-miss" diagnoses, where delay changes outcome:
- Acute coronary syndrome (unstable angina / MI) — pressure or tightness, exertional, radiation to arm/jaw, diaphoresis, nausea. ECG and troponin are the priority tests.
- Aortic dissection — abrupt tearing pain, inter-arm blood-pressure difference, pulse deficit, widened mediastinum.
- Pulmonary embolism — pleuritic pain, dyspnoea, tachycardia, hypoxia, risk factors (immobility, malignancy, recent surgery).
- Tension pneumothorax — sudden pleuritic pain and breathlessness, tracheal deviation, absent breath sounds.
- Oesophageal rupture (Boerhaave) — severe pain after forceful vomiting, subcutaneous emphysema.
- Cardiac tamponade — hypotension, muffled heart sounds, raised JVP (Beck's triad).
Step 2 — a by-system differential
Once the emergencies are addressed, a by-system framework keeps the differential broad and structured. Chest pain can arise from the thoracic contents, the chest wall, the abdomen, or have a psychological origin:
- Cardiac — stable angina, pericarditis, myocarditis, acute heart failure.
- Vascular — aortic dissection, thoracic aortic aneurysm.
- Pulmonary — pulmonary embolism, pneumonia, pleurisy, pneumothorax.
- Gastrointestinal — gastro-oesophageal reflux, oesophageal spasm, peptic ulcer disease, biliary or pancreatic pain.
- Musculoskeletal — costochondritis, chest-wall strain, rib injury.
- Psychological — anxiety and panic disorder (a diagnosis of exclusion).
Taking the history
The SOCRATES framework structures the pain history: Site, Onset, Character, Radiation, Associations, Time course, Exacerbating/relieving factors, Severity. Beyond the pain itself, capture cardiovascular risk factors (age, smoking, diabetes, hypertension, hyperlipidaemia, family history), thromboembolic risk factors, and the response to any treatment already given (noting that relief with an antacid or GTN does not reliably confirm the cause).
Examination
- Vital signs including bilateral blood pressure and oxygen saturation.
- Cardiovascular exam — heart sounds, murmurs, a third heart sound, JVP, peripheral pulses.
- Respiratory exam — air entry, added sounds, signs of pneumothorax or effusion.
- Chest wall — reproducible tenderness on palpation (supports a musculoskeletal cause but never excludes a dangerous one).
- Legs — signs of deep vein thrombosis supporting PE.
Features that shift probability
No single symptom or sign confirms or excludes a cardiac cause, but some findings meaningfully move the probability, per the American Family Physician review:
- Pain radiating to both arms raises the likelihood of acute MI (positive likelihood ratio ≈ 7.1).
- A third heart sound or hypotension further increases suspicion of a cardiac cause.
- Chest-wall features — localised tenderness, stinging pain, reproducibility on palpation, absence of cough — modestly raise the likelihood of a musculoskeletal cause (combined positive LR ≈ 3.0).
- Burning retrosternal pain with acid regurgitation points toward reflux — but a benign feature must never close the book before the dangerous causes are excluded.
Investigations and risk stratification
Objective testing, not clinical gestalt, settles the question. A 12-lead ECG should be obtained early in anyone with possible cardiac chest pain, and serial high-sensitivity troponin is central to ruling ACS in or out. Validated risk scores — such as the HEART score (History, ECG, Age, Risk factors, Troponin) — help stratify risk and guide disposition. D-dimer and CT pulmonary angiography address suspected PE; CT angiography addresses suspected dissection. Always apply the thresholds and pathways in your local or national guideline.
Atypical presentations to watch
Textbook chest pain is not universal. Women, older adults and people with diabetes more often present atypically — with breathlessness, fatigue, nausea, epigastric discomfort or no pain at all — and these groups are at higher risk of a missed myocardial infarction. A lower threshold for objective testing is warranted when the presentation is atypical but the risk profile is concerning.
Red flags that warrant urgent action
- Haemodynamic instability — hypotension, tachycardia, poor perfusion.
- Hypoxia or acute breathlessness.
- Tearing pain, inter-arm BP difference, or a pulse deficit.
- Diaphoresis, pain radiating to both arms, or an abnormal ECG.
- Syncope accompanying the chest pain.
This is a reference, not a protocol
Risk stratification and management should use ECG, troponin and a validated risk score within your local or national pathway. Diagnostic uncertainty in chest pain is resolved by investigation and observation, not by clinical impression alone.
How clinical decision support helps
A structured differential is exactly where decision support earns its place. Shifaa AI's differential-diagnosis support surfaces a ranked differential with confidence levels, flags the red-flag presentations — ACS, dissection, PE — ahead of everything else, and cites the guidance behind each suggestion so you can check it. It widens and speeds your reasoning; it does not make the call. As we argue in can AI diagnose patients?, a diagnosis is a clinical judgement with accountability attached — the doctor decides, every time.
Frequently asked questions
What are the most dangerous causes of chest pain?
The classic "can't-miss" causes are acute coronary syndrome, aortic dissection, pulmonary embolism, tension pneumothorax, oesophageal rupture and cardiac tamponade — all exclude-first diagnoses because delay changes the outcome.
How do you rule out a heart attack?
History and examination alone are not sufficient. An early 12-lead ECG and serial high-sensitivity troponin, interpreted with a validated risk score such as the HEART score and your local pathway, are what rule acute coronary syndrome in or out.
What is the HEART score?
A validated risk-stratification tool for chest pain scoring History, ECG, Age, Risk factors and Troponin to estimate the short-term risk of a major adverse cardiac event and guide disposition. Use it within your local protocol.
Can AI diagnose chest pain?
No. AI decision support can surface a ranked differential, flag red flags and cite guidance — but a diagnosis is a clinical judgement the doctor makes, supported by ECG, troponin and risk scoring. The tool assists reasoning; it does not decide.
References
- Outpatient evaluation of chest pain / diagnosis of acute coronary syndrome. American Family Physician (AAFP). aafp.org
- Differential Diagnosis of Chest Pain. IntechOpen (open-access, 2020).