Low alkaline phosphatase is relatively rare. If it is slightly low, it is usually of no clinical significance. If it is significantly low, it can be seen in renal diseases, hypothyroidism, malignant tumors and other diseases. Alkaline phosphatase is mainly found in human liver, bone, kidney and other organs or tissues, and is an important indicator of extrahepatic biliary obstruction, intrahepatic space-occupying lesions and bone disease. Clinically, high alkaline phosphatase is usually more common, low alkaline phosphatase is rare, if it is slightly low, usually has no clinical significance, can be seen in normal people. However, if the low alkaline phosphatase level is high, it can be considered as a result of pathologic factors. Patients with malnutrition, hypothyroidism, pernicious anemia, etc. have a decreased metabolic capacity, which reduces protein synthesis and leads to lower alkaline phosphatase levels. Renal diseases, such as chronic nephritis, increase the glomerular filtration rate and the body loses more protein, which lowers alkaline phosphatase. In addition, certain wasting diseases, such as gastric cancer, liver cancer, lung cancer and other malignant neoplastic diseases, will cause the body to consume more protein, and even malignant disease, resulting in a significant decrease in alkaline phosphatase. If the patient has low alkaline phosphatase for a long time or repeatedly, it is recommended to consult a doctor in time to identify the cause of the disease and carry out targeted treatment to avoid delaying the condition.