Differential Diagnosis

Emergency Department Differential Diagnosis

Pediatric
DDx by Symptoms — AIToxicology DDx — Toxidromes
Cardio / Pulm
Chest Pain
ACS · PE · Dissection
Hypertension
Urgency vs emergency
Hypotension
Shock — type & cause
Palpitations
Arrhythmia screen
Shortness of Breath
Dyspnea workup
Syncope
Cardiac vs reflex
Neuro
Altered Mental Status
AEIOU-TIPS
Dizziness / Vertigo
Central vs peripheral
Headache
SAH · meningitis
Seizure
First-time vs known epilepsy · status
Weakness
Focal vs global
Abdo / GU
Abdominal Pain
Surgical screen
Back Pain
Red flags · cord · vascular
Dysuria
UTI · STI · obstruction
Flank Pain
Renal colic · pyelo · AAA
Vaginal Bleeding
Pregnant vs non-pregnant
Vomiting / Diarrhea
Volume + electrolytes
Musculoskeletal
Ankle Pain
Maisonneuve · syndesmosis · septic
Arm Pain
MI · compartment syndrome · fracture
Foot Pain
Lisfranc · puncture · ischemia
Hand Pain
Tendon sheath · fight bite · ischemia
Hip Pain
Septic · occult fx · vascular
Knee Pain
Septic · ligament · referred hip
Leg Pain (lower)
DVT · compartment · arterial
Rib Pain
PTX · flail · cardiac
Shoulder Pain
MI · dissection · septic joint
Thigh Pain
DVT · compartment · femur fx
Wrist Pain
Scaphoid · DRUJ · septic
General
Anxiety
Diagnosis of exclusion — rule out organic
Diarrhea
Infectious vs inflammatory
Dry Mouth
Xerostomia · dehydration · Sjögren
Fever
Source + sepsis
Nausea / Vomiting
GI · CNS · metabolic
Rash
Dermatologic emergencies
Trauma
Primary survey

Educational reference only. Not a substitute for clinical judgment or local protocols.