Why are allergies becoming more common?
No one knows for sure. There are various theories why this might be, with the “hygiene hypothesis” representing the most popular reason. The “hygiene hypothesis” refers to the fact that in our clean, modern society, our immune systems no longer have to fight off multiple infections during childhood. The absence of infections results in the immune system shifting away from an “infection fighting” stance towards an “allergies” stance.
These two different stances represent opposites as far as our immune system is concerned.
