The common side effects of morphine are addiction and dependence after a week or so of use. It is an opioid receptor antagonist, and the common side effects are difficulty in urination or inhibition of intestinal motility that induces constipation. Prolonged use of the drug is also prone to liver and kidney damage, and allergic reactions may manifest as a peripheral rash. For patients with cerebrovascular disease, morphine may cause an increase in intracranial pressure, resulting in headache, dizziness, and even nausea and vomiting. The indications and contraindications for the use of morphine should be strictly controlled. For patients with advanced tumor, the main purpose is to relieve pain, and the occurrence of side effects can be relatively ignored. It should also be noted that there are some patients, especially the malignant tumors of respiratory tract, the application of morphine is prone to excessive sedation, leading to the occurrence of respiratory depression, and attention should be paid to prevent the occurrence of adverse reactions.