The Cobalt (blood) test measures the level of cobalt in the bloodstream, often to assess exposure or monitor individuals with metal-on-metal hip implants. Elevated cobalt levels may indicate excessive exposure, which can potentially lead to toxic effects affecting the heart, thyroid, or nervous system. This test aids in evaluating cobalt toxicity and may be used alongside other tests to assess overall metal exposure. Proper patient preparation, such as avoiding metal-based supplements, may be required before the test for accurate results.