There are many types of painkillers, different painkillers have different effects, there is no instant painkillers, you should choose the appropriate painkillers according to the different conditions. Common painkillers are aspirin, ibuprofen, paracetamol, acetaminophen, tramadol, morphine, methadone, pethidine (dulcolax), poppycine, remifentanil and so on. Commonly categorized into non-steroidal anti-inflammatory analgesics and opioid analgesics, different painkillers have different effects and should be selected according to the different conditions of the corresponding painkillers. Non-steroidal anti-inflammatory analgesics, such as aspirin, ibuprofen, etc., have a mild analgesic effect and are mainly used for patients with mild pain, and common side effects of the above drugs include nausea and vomiting. Opioid analgesics, such as tramadol, morphine, methadone, pethidine (dulcolax), etc., are potent analgesics with significant analgesic effects, and are generally used for patients with more severe pain. Opioids may cause immunosuppression, can also cause chest wall, abdominal wall muscle stiffness; can also cause respiratory depression, life-threatening. Some are also addictive. Painkillers are more varied and fast-acting, but they must be taken under strict medical supervision, according to the condition, and in the amount needed.