LDH is an enzyme that is found in cells throughout the body. The LDH value is elevated whenever there is any sort of cell damage/turnover. This means there are many situations in which an elevated LDH is totally normal. For example, older women who are undergoing bone loss from lack of estrogen, or children who are growing have normal high LDH. In cancer the LDH is of interest because a high LDH can typically indicate cell death that is cancer cell death, whether from chemo or tumor necrosis.