Hypophosphataemia and Hyperphosphataemia in a Hospital Population

One hundred cases of hypophosphataemia (≤ 2·0 mg/100 ml) and 84 cases of hyperphosphataemia (≥ 5·0 mg/100 ml) occurring in a hospital population were studied in order to determine the cause of the abnormality. Examples of hyperphosphataemia due to renal failure were excluded from the study. A low serum phosphorus concentration was most frequently due to intravenous administration of carbohydrate, usually glucose, which accounted for 40% of cases. The next commonest cause was vomiting (12%). No obvious explanation could be found in 26% of cases, but in most of these factors were present which are known to affect phosphorus metabolism. No one cause of hyperphosphataemia was outstanding in frequency and in over 50% of cases no definite explanation for the abnormality could be found.