Copper, Serum or Plasma

Copper is a mineral your body needs in small amounts to keep your blood cells, nerves, bones, and immune system healthy. A blood or urine test can check whether your copper levels are too low or too high. Low copper can cause anemia, low white blood cell counts, and nerve problems, while too much copper—sometimes due to a genetic condition called Wilson disease—can harm the liver and brain. Your doctor may also check a related protein called ceruloplasmin to get a fuller picture of how your body is handling copper. This test is most meaningful when interpreted alongside your symptoms, other lab results, and your medical history.

When elevated: Elevated serum copper may indicate Wilson disease (paradoxically in some presentations), copper toxicity from dietary or environmental exposure, inflammatory or acute-phase states, estrogen therapy or oral contraceptive use, pregnancy, liver disease, or certain malignancies. Chronic copper excess can cause hepatic cirrhosis, hemolytic anemia, and neuropsychiatric symptoms. When low: Low serum copper suggests copper deficiency, which can result in hypochromic anemia refractory to iron therapy, neutropenia, osteoporosis, and progressive myeloneuropathy. In Wilson disease, low ceruloplasmin with elevated free (non-ceruloplasmin-bound) copper and elevated urine copper is the characteristic pattern. Severe deficiency may impair immune function and wound healing.

Copper supports aerobic energy production and antioxidant defense during intense training, making it relevant for endurance athletes and those with high oxidative stress. Adequate copper is also essential for collagen and connective tissue integrity, which supports joint health and injury resilience in active individuals.