Disease-mongering--convincing the healthy that they are sick or the slightly ill that they are very sick--is big business, says Payer (How to Avoid a Hysterectomy, 1987). According to Payer, competition in medical services has led health-care providers and drug companies to seek a larger market by convincing more people--if they have insurance--that they need their services and products. Also guilty of disease-mongering, she contends, are medical writers who hype diseases to get their stories published; medical researchers and disease-fighting organizations competing for funding; makers of diagnostic devices eager to sell their equipment; and a legal system that encourages doctors to practice defensive medicine--i.e., to overtest and overtreat. Payer warns that defensive medicine not only wastes time and money and exposes the patient to unnecessary, and possibly risky, procedures, but can lead to uninsurability: An overdiagnosis intended to guarantee that a patient's visit is covered by insurance may well become a blot on that patient's medical records should the patient later apply for a policy with another insurer. Payer's solution: a system of national health insurance that doesn't reward overdiagnosis or overtreatment. Meanwhile, the author notes, everyone's best bet is to become an informed consumer and to keep disease in proper perspective. Payer can be persuasive when she looks at pharmaceutical companies' marketing tactics, hospitals' responses to Medicare regulations, the overselling of minor conditions as serious diseases, and the promotion of unneeded corrective surgery, but her case seems weaker when she tackles risk reduction and disease prevention. In discussing risk factors for heart disease, for example, she overlooks Dr. William Castelli and his decades-long Framingham study. A worthwhile warning that attempts to hit too many targets, reducing its impact.