Suddenly the hand cannot open like a chicken’s claw, it may be a low blood calcium loss and lower blood calcium, which can cause muscle spasms, and the patient may have the above symptoms, or leg cramps, which can manifest as calf pain, or bone pain, mainly due to osteoporosis. In case of infants and children with a history of low blood calcium, there may be incomplete closure of fontanelle and growth deformities, patients may develop chicken chest and rickets, etc. Some affected children may also show various symptoms such as hair loss. It should be treated with calcium supplementation in a timely manner. Calcium gluconate can be given orally or intravenously to correct it quickly, which may cause cardiac arrest and even affect the patient’s life in case of severe hypocalcemia. Patients with low blood calcium may be due to increased calcium requirements or to increased calcium destruction. Hypocalcemia is also likely to occur if the patient has hypertension and is on long-term oral calcium antagonists.