The main hazards and side effects of magnesium sulfate include hot flashes, sweating, dry mouth, nausea and vomiting, respiratory depression, constipation, hypocalcemia, edema, and may lead to hypermagnesemia in newborns. Magnesium sulfate is an anticonvulsant that lowers blood pressure, and is mainly used clinically for the treatment of pregnancy hypertension, pre-eclampsia and eclampsia. It is contraindicated for breastfeeding women, patients with myocardial damage and heart block. Magnesium sulfate is usually administered intravenously, and patients may experience symptoms such as hot flashes, sweating, dry mouth, etc. If it is administered too quickly intravenously, it may also cause nausea and vomiting, panic, dizziness and nystagmus. When the dosage is large, there may be dull sensory response, loss of knee tendon reflexes, respiratory depression, and cardiac arrhythmia. If magnesium sulfate is used continuously, it may also cause constipation and paralytic intestinal obstruction, which usually resolve gradually after the drug is stopped. A few patients may also develop hypocalcemia (manifested as convulsions, spasms, etc.), pulmonary edema, skin rash, hypotension, shock, etc. As magnesium ions can pass through the placenta, the use of large quantities may also cause neonatal hypermagnesemia, which is mainly manifested by low muscle tone, poor sucking, inactivity, inactive, inaudible crying, etc., and even respiratory depression. When using magnesium sulfate, it is recommended to consult a doctor in advance and use it strictly according to the doctor’s instructions, and not to use the medicine on your own, so as not to delay or even aggravate the condition.