Hyperkalemia Hyperkalemia may only become apparent when a person's platelet concentration is more than 500,000/microL in a clotted blood sample (serum blood sample). Potassium leaks out of platelets after clotting has occurred. On the other hand, processing of heparinised, unclot blood does not cause falsely elevated potassium. In addition to that, high white cell count (greater than 120,000/microL) in patient with chronic lymphocytic leukemia increases red blood cells fragility, thus causing pseudohyperkalemia during blood processing. This problem can be avoided by processing serum samples, because formation of clot protect the cells from haemolysis during processing. A familial form of pseudohyperkalemia may
Blood bone marrow in a process called hematopoiesis, which includes erythropoiesis, the production of red blood cells; and myelopoiesis, the production of white blood cells and platelets. During childhood, almost every human bone produces red blood cells; as adults, red blood cell production is limited to the larger bones: the bodies of the vertebrae, the breastbone (sternum), the ribcage, the pelvic bones, and the bones of the upper arms and legs. In addition, during childhood, the thymus gland, found in the mediastinum, is an important source of T lymphocytes. The proteinaceous component of blood (including clotting proteins) is produced predominantly by