In clinical practice calcium injections are mainly used to treat calcium deficiency, acute calcium loss, as well as magnesium and fluorosis, and allergic diseases. Commonly used calcium are calcium gluconate, calcium chloride, and calcium vidin. Side effects are more likely to occur when calcium injections are given, especially when given intravenously. It is easy to cause hypercalcemia when given intravenously, and the resulting clinical disorders, such as common cardiac arrhythmias, which in severe cases can even lead to sudden cardiac arrest. Some patients may experience generalized fever, nausea, vomiting, and in some cases, dry stools and headache. The injection site is prone to hard nodules, which can easily lead to severe pain and tissue necrosis if they inadvertently leak outside the blood vessels.