The text is a prominent medical reference authored by Professor Walter Siegenthaler . It is widely considered a classic clinical textbook, particularly in Europe, where it has reached its 19th edition in German. Core Concept and Purpose

It uses functional systems and "symptom constellations" to guide users from a clinical sign to a definitive diagnosis.

Designed to be both a comprehensive textbook and a simple, easy-to-use clinical reference. Example Differential Logic

It is a resource for medical students, residents, and practitioners across various specialties including internal medicine, dermatology, neurology, and rheumatology. Key Features of the Reference

The textbook and similar symptom-based guides help clinicians evaluate overlapping symptoms. For instance: