Lactate is a product of anaerobic glucose metabolism. It accumulates in the blood in states where anaerobic glucose metabolism is increased, such as circulatory disorders or strenuous physical exercise, or when lactate removal is disturbed. Elevated lactate concentrations are associated with mortality risk in several conditions. Good blood sampling and processing techniques should be used when evaluating lactate, since both prolonged venous stasis during blood sampling and delayed plasma/serum separation from red blood cells increase lactate concentrations.