Calcium deficiency can be comprehensively judged by the clinical manifestations of patients and auxiliary examination methods such as blood calcium measurement and bone densitometry. 1、Clinical manifestations: Calcium deficiency refers to the state of calcium deficiency in the body, patients can appear perioral numbness, muscle spasms, tetany, convulsions and other neurological reactions, but also bone pain, pathological fractures, bone deformities, decreased immunity, irritability, etc., and in severe cases, it can lead to cardiac arrhythmia, epileptic seizures and even apnea. 2、Blood calcium measurement: the normal serum calcium concentration of adults is 2.25~2.75mmol/L, when the blood calcium concentration <2.25mmol/L, for hypocalcemia. 3、Bone densitometry: Bone density is examined by ultrasound and dual-energy X-ray, thus reflecting the amount of minerals in the bones. When patients have symptoms such as bone pain and muscle spasm, they should consult the doctor in time, and the doctor will improve the relevant examination to further clarify the diagnosis, evaluate the degree of calcium deficiency and carry out targeted treatment. Patients should not blindly judge on their own, so as not to affect the condition.