A silent epidemic of chronic and "invisible" illnesses afflicts tens of millions of Americans: these are diseases that are poorly understood, are frequently marginalized, and can go undiagnosed and unrecognized altogether. Drawing on her own medical experiences as well as a decade of interviews with doctors, patients, researchers, and public health experts, renowned writer Meghan O'Rourke reveals how inherited ideas have led us to ignore a host of hard-to-understand medical conditions, ones that resist easy description or simple cures. Blending lyricism and erudition, candor and empathy, O'Rourke brings together her talents and roles as critic, journalist, poet, teacher, and patient, synthesizing the personal and universal into one monumental project arguing for a seismic shift in our approach to disease. The Invisible Kingdom offers hope for the sick, solace and insight for their loved ones, and a radical new understanding of our bodies and our health to help all of us through this new frontier.