A century ago, most allergies were not even recognized; today, they’re a global burden. There are over 200 allergens out there that affect people and their ability to live their lives normally. While medications can effectively treat certain allergies, there is no one solution for all of them and the problem is quickly growing. Why is this? It is widely thought that the shift in our lifestyles and how we spend more and more time indoors could be a significant contributing factor. But hiding within your home are a host of indoor allergies that cause misery to millions. You just have to know where to look.