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
Sweat test sodium chloride (salt). Secretion entails the movement of salt and water from sweat gland cells into the sweat duct. Reabsorption occurs in the duct with the movement of salt from the sweat back into sweat duct cells. What remains is sweat, a salt solution with a relatively finely tuned concentration of sodium and chloride. For normal salt reabsorption to occur, individual ions of sodium and chloride must be taken from the sweat and moved back into cells of the sweat duct. These ions are moved by transporters called ion channels. In the case of sodium, there is a sodium channel;