Update on screening for type 2 diabetes. The why, who, how, and what of testing and diagnosing.

Type 2 diabetes can cause serious complications even as it remains undiagnosed. Screening is recommended only in people with risk factors for the disease. The ADA recommends FPG as the test of choice, but RPG is also a practical alternative because it is easier and more convenient. Frequency of rescreening if the first screen result is normal depends on the number of risk factors present. Physicians should realize the importance of a confirmatory test and not base a diagnosis of diabetes on a single value unless the value is so high that the diagnosis is unequivocal.