Background: Three years ago, Diane Terry, 60, began to cough. Doctors tested her for Valley fever and other lung diseases and allergies -- and found nothing. They tried medicines to stop the coughing, but nothing worked. [See a video of Diane Terry]Why she left: She discovered that the coughing subsided when she left her native Selma to stay at a mobile home in Pismo Beach that she and husband Dan Terry, 59, bought for retirement.Now: Diane spends most of her time alone in Pismo, seeing her husband and children mostly on weekends. She quit a job she enjoyed as a vocational nurse at Sun-Maid Growers of California. When she returns to visit doctors and family in Selma, Diane can only go outdoors wearing a hood that filters the air: "It's affected my whole life."