Physicians in the 21st century can diagnose almost any ailment. Hi-tech machines can identify what's happening within a person's brain. Surgeons can operate inside someone through nothing more than a tiny incision. And drugs can cure, or at least control, a wide range of illnesses. Yet it hasn't always been this way. Many people once died because operations were carried out using dirty knives. Some remedies were as bad as the diseases they were supposed to prevent. This book looks at the advances that have taken place in the world of medicine since earliest times.