Differential Diagnoses. Think Like a Clinician.
Differential Diagnoses. Think Like a Clinician.
Every DDx is mapped to multiple learning modes, from rapid reference to interactive clinical reasoning. across specialties, build the pattern recognition and structured thinking that examiners test.
From the most common acute presentations to the high-yield rare diagnoses, the DDx engine builds the systematic clinical thinking that separates good candidates from great ones.
Clinical Specialties. Clinical Presentations.
Highest Yield
- Gastroenterology (20 presentations, largest)
- Neurology (13 presentations)
- Cardiology (12 presentations)
- Endocrinology (10 presentations)
- Respiratory (8 presentations)
- Haematology (8 presentations)
Core Specialties
- Nephrology and Urology (7 presentations)
- MSK and Rheumatology (4 presentations)
- ENT (4 presentations)
- Paediatrics (4 presentations)
- Surgery (4 presentations)
- Dermatology (3 presentations)
Focused Areas
- Psychiatry (2 presentations)
- Emergency Medicine (2 presentations)
- Gynaecology (2 presentations)
- Ophthalmology (2 presentations)
- Infectious Disease (1 presentation)
5 Modes. One Presentation.
Every differential diagnosis has 5 ways to study it. Choose the mode that matches how you learn best.
Mode 1: Deep Dive
Complete clinical analysis with pathophysiology, epidemiology, and full diagnostic workup for each differential.
Mode 2: Quick Reference
Rapid differential list with key distinguishing features, ideal for last-minute revision before exams.
Mode 3: Reason-It
Interactive clinical reasoning. Work through the case step by step, narrowing your differential with each new clue.
Mode 4: Flowchart
Visual decision pathway from presentation to diagnosis. See how clinical features branch into different diagnoses.
Mode 5: DDx Cards
Flip cards with the diagnosis on the front and key distinguishing features and discriminating investigations on the back.
Sample: Acute Chest Pain
See how MedNext presents a differential: likelihood-ranked, colour-coded, with distinguishing features at a glance.
Presentation: A 42-year-old male presents to A and E with sudden-onset sharp chest pain, worse on inspiration. He is tachycardic and mildly hypoxic. No cardiac history. Smokes 10 a day. Flew long-haul 48 hours ago.
Ranked differential: ACS (35%), Musculoskeletal (30%), PE (20%), Pneumothorax (15%).
The full case includes distinguishing features, key investigations, and all multiple learning modes for each differential.
Worked example: how a chest pain differential is built
The same 42-year-old from the sample above. Rather than a random list, you build the differential by anatomical system, then let discriminating features raise or lower each diagnosis. This is a taste of the reasoning inside every one of the 106 differentials.
Cardiac
- Acute coronary syndrome raised by central pressure, radiation to arm or jaw, diaphoresis; investigate with ECG and serial troponin.
- Pericarditis raised by sharp pain, worse lying flat and better sitting forward, with a rub.
Respiratory
- Pulmonary embolism raised by pleuritic pain, breathlessness, recent long-haul flight and hypoxia; use a Wells score to guide D-dimer versus imaging.
- Pneumothorax raised by sudden pain with reduced breath sounds on one side.
- Pneumonia raised by fever, productive cough and focal crackles.
GI and MSK
- Gastro-oesophageal reflux raised by a burning, food-related pain relieved by antacids.
- Musculoskeletal (costochondritis) raised by localised pain reproduced on chest-wall palpation.
- Discriminator: reproducible-on-palpation points to the wall, but never let it stop you excluding the dangerous cardiac and respiratory causes first.
A second short differential: acute headache
Different presentation, same structured method. Sort by what you must not miss, then by what is common.
Cannot-miss causes first. Subarachnoid haemorrhage suggested by a thunderclap, maximal-at-onset headache; meningitis by fever, neck stiffness and photophobia; raised intracranial pressure by a headache that is worse in the morning, on lying flat or on straining, with visual changes; giant cell arteritis in an older patient with scalp tenderness, jaw claudication and a raised ESR.
Then the common causes. Tension-type headache with a bilateral band-like ache, migraine with a unilateral throbbing headache plus nausea, photophobia and sometimes aura, and cluster headache with severe, strictly unilateral peri-orbital pain and autonomic features such as a watering eye.
The red-flag features are what convert a routine headache into an urgent one. The full differential engine walks you through the discriminating question, the key investigation and the safe next step for each. This is a taste of what is inside; the full interactive tool is in the MedNext app.
Think Systematically. Every Time.
differential diagnoses across specialties, each with multiple learning modes. Build the structured clinical thinking that separates good candidates from great ones.
Explore All differential diagnoses