Such regularities were examined through the cases accumulated in our hospital for 4 years, including the proportion of hypernatremia in patients with brain death, when hypernatremia increases in brain‐dead patients, whether hypernatremia is related to the urine output and the NT‐proBNP, and whether the blood creatinine and use of mannitol were related. This evidence concerns the gene NPPB and Hypernatremia.