There are multi but limited factors can make you sick in this world, the first one is emotions, the second one is the weather, the third one is foods & drinks, work & leisure, sex and heredity. The emotions play the first important role in your health, because emotions are from the mind/soul/spirit, mind decides the action, the action decides the results, what kind of mind you have, what kind of life you will have; the second and the third factor are just in the second position for your sickness.