People lived in mud and timber without proper ventilation and sanitation.They could have fleas or lice.
People ate a much healthier diet than they do nowadays, so the illness were rare. The only thing is that there were no antibiotics to fight infection so many people died because of illness.
There were very few towns and no large cities.
People were unable to read and write. Only a few people however mainly monks,were educated to a higher level.
Communities often had good knowledge for example herbal medicine and they were unable to say why certain remedies seemed to work and relied on a system of trail and error and superstition to make sense of their world.
There were churches but that didn't mean that people behaved better than normal.