When the human body is subjected to external trauma there will be different degrees of pain, some of which can be tolerated, and for severe trauma or post-operative pain, the appropriate pain medication will be used to relieve the pain according to the patient’s pain condition. The first type of painkillers, non-steroidal anti-inflammatory painkillers, are used for muscle swelling and pain or joint pain, such as ibuprofen and celecoxib. The second type of painkillers, weak opioids, are used for severe pain and pain that interferes with life, such as tramadol. The third type of painkillers, strong opioid painkillers, are only used when the pain is very severe, such as oncological pain, commonly used are morphine, dulcolax, fentanyl, etc. These drugs cannot be used casually, and usually require a doctor’s hand-signed prescription for poisonous anesthesia, which is suitable for patients with advanced cancer, and painkillers must be used according to medical advice.