A cadmium test measures the concentration of the toxic heavy metal cadmium in blood, urine, or hair samples. Cadmium exposure typically occurs through industrial workplaces, tobacco smoke, contaminated food, or batteries, and the metal can accumulate in organs such as the kidneys and liver over time. This diagnostic test is primarily used to assess acute or chronic heavy metal toxicity, monitor occupational safety compliance, and investigate unexplained renal dysfunction or bone mineral loss. Because cadmium has a long biological half-life, clinical evaluation helps guide removal from exposure sources and directs supportive medical management.

The cadmium spot urine test measures the level of the toxic heavy metal cadmium in a random urine sample, offering a snapshot of current bodily burden and renal excretion. Because cadmium accumulates primarily in the renal cortex over a long biological half-life, urinary testing is especially useful for evaluating chronic exposure and assessing potential kidney dysfunction. Clinicians typically order this test to monitor occupational safety compliance among industrial workers, investigate heavy metal toxicity, or track environmental exposure risks. Results are often normalized against urine creatinine to account for hydration variations and guide appropriate medical management.

A caesium test measures the concentration of the heavy metal caesium in biological samples such as blood or urine. While naturally occurring stable caesium poses minimal health risks, radioactive isotopes like caesium-137 can be released through nuclear accidents or industrial incidents, leading to internal contamination and radiation exposure. This diagnostic test is primarily used in emergency toxicology, occupational surveillance, and environmental medicine to detect exposure, quantify body burden, and guide mitigation or decorporation therapies, such as Prussian blue administration. Clinicians interpret test results alongside exposure history to evaluate potential health hazards and determine appropriate medical interventions.

The calcitonin test measures the level of the hormone calcitonin in the blood, which is primarily produced by the parafollicular C-cells of the thyroid gland. Calcitonin's main role is to help regulate calcium and phosphate levels in the blood, opposing the action of parathyroid hormone. The primary clinical utility of this test is to screen for and monitor medullary thyroid cancer (MTC), a rare type of thyroid tumor originating from C-cells. Elevated calcitonin levels are highly indicative of MTC, and the test is also used to assess treatment response and detect recurrence after surgery. It may sometimes be used in conjunction with a calcium stimulation test to enhance diagnostic accuracy.