Isabel Healthcare provides a clinical reasoning support tool to help physicians broaden their differential and manage clinical uncertainty. The Isabel tool uses the patient's demographics and clinical features to generate a list of possible diseases covering over 10,000 conditions. It covers all age groups and can take into account travel history. Clinicians around the world rely on Isabel to provide them with inspiration, particularly for patients with complex or atypical presentations, when they need it most. Isabel also produces a version for patients: the Isabel Symptom Checker which helps patients research possible causes for their symptoms and provides a triage tool to help them decide where to present if seeking care.