Health effects of heavy metals have been widely investigated, but further evaluation is required to comprehensively delineate their toxicity. Using data from the 2007–2008 National Health and Nutrition Examination Survey, a multivariate logistic regression analysis was performed on 1,857 adults to examine the relationship between urinary heavy metals and various medical conditions. Cardiovascular diseases were correlated to cadmium (OR: 4.94, 95% CI: 1.48–16.56) and lead (OR: 5.32, 95% CI: 1.08–26.21). Asthma was related to tungsten (OR: 1.72, 95% CI: 1.15–2.59) and uranium (OR: 1.52, 95% CI: 1.01–2.28). Hepatotoxicity was associated with molybdenum (OR: 3.09, 95% CI: 1.24–7.73) and uranium (OR: 4.79, 95% CI: 1.74–13.19). Surprising inverse relationships occurred for excessive weight with lead (OR: 0.72, 95% CI: 0.52–0.98), reduced visual acuity with cobalt (OR: 0.65, 95% CI: 0.44–0.95) and cesium (OR: 0.52, 95% CI: 0.35–0.77). This study supports some previous evidence of potential relationships and provides insights for future research.