Invisible Illness

Rare diseases are considered medical exceptions. Each one affects only a few people, and many appear statistically negligible. And yet, the probability of suffering from a rare disease in the course of one's life is high. So why are these diseases so often overlooked, misinterpreted, or only recognized after years? This book explores the question of why modern medicine-despite high technology, guidelines, and evidence-based procedures-systematically reaches its limits when it comes to rare diseases. It shows that diagnostic delays are not an individual failure, but the result of structural conditions: probabilistic thinking, fragmentation of care, time pressure, economic incentives, and the premature psychologization of unexplained symptoms. Based on an analytical examination of medical decision-making logic, the book uses specific examples of diseases to illustrate how rare diseases "disappear" in everyday clinical practice. It describes the diagnostic odyssey of many affected individuals, the psychological consequences of prolonged uncertainty, and the paradoxical situation in which normal findings often obscure rather than clarify. It becomes clear that rare diseases are not difficult to recognize because they are exotic, but because they do not fit into the usual patterns. Rare diseases do not appear here as a marginal topic, but as a touchstone. Those who understand why they are overlooked understand more about the strengths-and blind spots-of modern medicine as a whole. Bremen University Press has published over 5,000 specialist books in various languages since 2005. January 2026