The history of express health tests is short; the first developments appeared around a hundred years ago. But they became widely known and publicly available only fifty years later. At the same time, the list of such health tests that could be used at home was limited to pregnancy tests, and later became wider. Today I would divide all rapid health diagnostic tests into two large groups: test kits that require professional personnel or equipment; and test systems that are so simple that they practically eliminate the possibility of error. Like all medical devices, rapid health testing kits are subject to oversight and regulation by the FDA. Rapid tests available for at-home use are labeled OTC, or “over the counter”. And according to the rules of CLIA (Clinical Laboratory Improvement Amendments), such express health test kits are under the CLIA-WAIVED category. This is necessary to know in order to understand the likelihood of error in assessing test results and to purchase the right health test kit.