High free calcium in the blood is considered to be caused by excessive intake or decreased excretion of calcium ions, as well as the presence of fractures or diseases such as hyperparathyroidism. The normal blood calcium range is 2.1 to 2.57 mmol/L. If it exceeds 2.5 mmol/L, it is important to be alert to the presence of elevated blood calcium. Common causes of high free calcium in the human body are: excessive intake of calcium ions, such as the human body every day to supplement calcium tablets, more than the amount of the body’s normal needs, will cause an increase in blood calcium The human body’s calcium ions to reduce the discharge, but also lead to high free calcium in the blood, such as the patient application of thiazide diuretics, the use of calcium after the decrease in the discharge of calcium, it will cause a transient hypercalcemia. If the patient will have a fracture, the calcium in the body will be absorbed when the fracture occurs, and there will be a mild increase in blood calcium. In addition, if the patient has endocrine disease, such as hyperparathyroidism, the hormone secreted by the parathyroid gland will be too high, and the symptoms of high blood calcium will appear. Therefore, the phenomenon of high free calcium, must go to the hospital, a professional doctor to identify the cause and guide the treatment.