Thirty years ago, Henry Gadsden, the head of Merck, one of the world"s largest drug companies, told Fortune magazine that he wanted Merck to be more like chewing gum maker Wrigley"s. It had long been his dream to make drugs for healthy people so that Merck could "sell to everyone." Gadsden"s dream now drives the marketing machinery of the most profitable industry on earth. Drug companies are systematically working to widen the very boundaries that define illness, and the markets for medication grow ever larger. Mild problems are redefined as serious illness and common complaints are labeled as medical conditions requiring drug treatments. Runny noses are now allergic rhinitis, PMS has become a psychiatric disorder, and hyperactive children have ADD. When it comes to conditions like high cholesterol or low bone density, being "at risk" is sold as a disease. Selling Sickness reveals how widening the boundaries of illness and lowering the threshold for treatments is...