There is a difference between hypocalcemia and hypocalcemia, the definition, etiology, and symptoms are different and need to be analyzed specifically. 1. Definition is different: low calcium is generally due to a variety of reasons induced by the body calcium content is insufficient; low blood calcium is the body blood calcium concentration & lt; 2.25mmol / L or ionized calcium & lt; 1.0mmol / L. 2. Different etiology: the etiology of hypocalcemia is generally induced by insufficient calcium content in the body or more calcium discharged from the body; hypocalcemia is generally induced by calcium malabsorption, hypocalcemic drugs and certain psychotropic drugs. 3. Symptoms are not the same: low calcium will generally cause bone fracture, osteoporosis, and underdevelopment of teeth and other symptoms; low blood calcium will induce symptoms of increased muscle excitability, as well as muscle spasms, cramps, and low back pain. In addition, both low calcium and low blood calcium have certain harmful effects, it is recommended that patients need to actively accept the treatment, do not be negligent, so as not to delay the condition.