Why More People are Getting Allergies and Why They’re Getting Worse

Allergies have intensified over the last few decades. An estimated 30 to 40 percent of the global population has some form of allergy, and experts say that number could rise to 50 percent by the year 2030. So what’s behind this? Research shows it’s a complicated picture, with climate change, our stress levels and genetics all playing roles. We talk to medical anthropologist Theresa McPhail, author of the new book “Allergic,” about what the latest research shows on diagnostics, treatment and what we can do to cope with our allergies in a “changing world.”