What Actually Happens When You Come to the ER with Chest Pain
The Question Behind This Quick Hit
“Dr Cois, what actually happens when I walk into the Emergency Department with chest pain? What are you guys thinking? What are you doing? And why does it take so long?”
This question keeps coming up — from patients in the bay, from family members in the waiting room, from medical students rotating through their first ED shift. So I made it the very first episode in our new Quick Hits bonus series: short, focused answers to the questions you actually ask.
Here’s the inside view of a chest pain workup.
Why We Move So Fast
Cardiovascular disease is the number one killer of people in high-income countries. So when someone walks through our doors clutching their chest, every alarm bell in the department goes off.
The diagnosis we are most worried about missing is a heart attack — and the metric we live and die by is door-to-balloon time. That is the time from when you walk through the ED doors to when an interventional cardiologist has a stent across the blocked artery in your heart, restoring blood flow.
The faster we do that, the more heart muscle we save. Cardiovascular mortality has dropped meaningfully over the last few decades — not because of magic, but because of better recognition, faster systems, and tighter teamwork. If it feels like everyone in the department is moving at a different speed when chest pain rolls in, that is by design.
The Three Body Systems Driving Every Chest Pain Workup
When a patient tells me they have chest pain, my brain runs through three main body systems: the heart, the lungs, and the gastrointestinal tract. There is also a fourth bucket — diagnoses of exclusion — that I will get to at the end.
1. The Heart
Top of the list: myocardial infarction — a heart attack. This happens when a cholesterol plaque that has been quietly building inside one of your coronary arteries for decades suddenly ruptures. A clot forms, blood flow stops, and the heart muscle downstream starts to die.
First test: an ECG — twelve sticky stickers and an electrical tracing of your heart. From the pattern, we can often tell which artery is blocked. If we see a STEMI pattern, you are going straight to the cath lab.
We will also draw blood for troponin (a protein that leaks out when heart muscle is damaged) and many of us will perform a bedside echocardiogram to look at how the heart is squeezing and check for fluid around the heart, which can suggest pericarditis — a usually post-viral inflammation we treat with anti-inflammatories.
2. The Lungs
Three big diagnoses here:
● Pneumonia — an infection of the lung. Usually bacterial or viral, often diagnosed with a chest X-ray and bloodwork.
● Pneumothorax — air trapped between your lung and chest wall, which deflates the lung. Treated with a chest tube. Yes, exactly what it sounds like.
● Pulmonary embolism — a blood clot, usually from a vein in the leg, that lodges in the arteries of the lungs. Can cause chest pain, shortness of breath, low oxygen, and in the worst case, cardiac arrest.
The gold-standard test for pulmonary embolism is a CT angiogram of the chest, but it carries a meaningful dose of radiation, so we don’t shotgun it. Instead, we ask risk questions: estrogen-containing medication, recent long flight, recent surgery, active cancer, history of clots.
3. The Gastrointestinal Tract
The most common GI cause of chest pain is reflux — stomach acid creeping up the oesophagus. Classic burning behind the breastbone, worse lying down. Annoying, but not dangerous.
The two scary GI causes are oesophageal rupture (a tear all the way through the food pipe) and a perforated peptic ulcer (where an ulcer in the stomach or duodenum erodes through the wall). Both need imaging, antibiotics, and surgery. Both are uncommon — but both are why we sometimes get a CT scan even when your heart looks fine.
The Honourable Mentions
A few extras worth a quick name-drop, because your ED doctor is absolutely thinking about them, even if they don’t mention them out loud:
● Aortic dissection — a tear in the lining of the aorta. Classically severe, tearing pain that radiates to the back. Diagnosed with a CT angiogram.
● Spontaneous coronary artery dissection — a heart-attack mimic that disproportionately affects younger women.
● Myocarditis — inflammation of the heart muscle, often post-viral.
● Oesophageal spasm — exactly what it sounds like.
● Musculoskeletal strain — the most common diagnosis you’ll go home with.
When I diagnose someone with musculoskeletal pain or gastritis in the ED, I always hedge. Because those are essentially diagnoses of exclusion. What I am really saying is: I have ruled out the things that will kill you tonight. The rest needs follow-up with your primary care doctor.
How Should This Modify Your Practice?
For patients:
● If you have chest pain that is new, severe, or doesn’t fit a pattern you recognise — come in. Don’t Google it. Don’t wait it out. Don’t text your cousin who’s a nurse. Come in.
● If you’ve been cleared in the ED, the work isn’t over. Chest pain is often a signal — sometimes a literal warning shot — that the foundations need attention. Blood pressure, cholesterol, sleep, stress, movement. The Tier 1 stuff.
● Follow up with your primary care provider. Diagnoses like “musculoskeletal pain” or “gastritis” are often diagnoses of exclusion in the ED — they need a longitudinal physician to fully work them up.
For early medical students and residents:
● Anchor your differential in three body systems first: cardiac, pulmonary, GI. Then layer the honourable mentions on top.
● Use risk-stratified reasoning before reaching for the CT angiogram. Radiation matters.
● Be honest with patients about what “gastritis” or “musculoskeletal pain” actually means in the ED context. Hedge appropriately and route them to follow-up.
About the Author
Dr Adrian Cois is an Emergency Medicine Physician and the host of Overheard in the Emergency Room. He writes and speaks about evidence-based preventive health for patients, healthcare professionals, and trainees.
Disclosures: No commercial conflicts of interest related to this content. Not medical advice — for educational purposes only.
Related Reading
● Episode 7 — Is Cholesterol Really the Villain?
● Episode 11 — Testing for Prevention
● Episode 1 — Why Your ER Doctor Won’t Shut Up About Prevention
References
Quick Hits are clinical overview episodes. References below point to canonical sources for the diagnoses discussed; full evidence deep-dives live in our standard episodes.
1. Gulati M, Levy PD, Mukherjee D, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain. Circulation. 2021;144(22):e368-e454.*
2. Konstantinides SV, Meyer G, Becattini C, et al. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2020;41(4):543-603.*
3. Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease. Circulation. 2010;121(13):e266-e369.
