During the Middle Ages, most people were sick with something for most of their lives. Newborns were often born small because their mothers had not had enough to eat when they were pregnant. Babies caught dysentery and typhoid from drinking water with sewage mixed in it. About a quarter of all babies died before they were a year old. Children caught one cold virus after another. They also were infested with worms that made them tired all the time. Mosquitoes gave them malaria.