Disease emergence and health transitions in the last millennium

For most of the first millennium, average expectation of life was only 30 or 40 years. The beginning of the 20th century saw the start of improvements, which by the century's end meant that a baby boy could expect an average 75 years of life, a baby girl even longer. The successes of the 20th century were not products of advances in medicine alone, but consequences of the great sanitary reforms that fuelled the public health movement in late Victorian Britain. However, health challenges also grew and changed: the rise in so-called modern epidemics (coronary heart disease, cancer, accidents and mental illness); the ageing of the population; the containment of the costs of rapid technological advances; the marked and intractable inequalities in health status between rich and poor, and between North and South. The dawn of a new millennium sees many of these health problems carried over from the late 20th century, whilst communicable diseases, once thought conquered, continue to pose a serious threat to human health because of their global significance. This paper traces progress in the health of the population and identifies some of the key challenges for medicine in the 21st century.