Diseases that were either non-existent or were much rarer before the development of human civilization. It's not an exact term: people can argue over when 'civilization' started. Some might start at the development of agriculture, millennia ago, others might talk about urbanification. A short list of such diseases would include: adult-onset diabetes, Alzheimer's syndrome, arteriosclerosis, some affective disorders, asthma and lung cancer. Some of these diseases are caused by environmental aspects of civilization: agriculture increases the starch content of the diet, increasing the risk of adult onset diabetes. Others are revealed by an extended lifespan: hunter-gatherers are susceptible to Alzheimer's disease, but rarely live long enough to suffer from it.