Pain pumps are more effective and suitable for patients with pain intolerance such as postoperative, tumor, etc. Side effects are relatively small. Common side effects of pain pumps are drowsiness, gastrointestinal symptoms, urinary retention and allergic reactions. 1. Drowsiness: Because most of the pain pumps use opioids with anesthetic and analgesic effects, the drug can inhibit respiration and reduce blood oxygen, resulting in drowsiness. 2. Gastrointestinal symptoms: pain pumps can slow down gastrointestinal motility, resulting in constipation, vomiting, abdominal distension and other symptoms. 3. Urinary retention: pain pumps can increase urethral tension, leading to urinary difficulties and urinary retention. 4. Allergic reactions: such as urticaria, local skin edema and other allergic reactions. The side effects of pain pumps are relatively minor and need not be overly concerned. If any of the above adverse reactions occur, discontinue use immediately.