Pain is a traumatic experience and discomfort for all patients, especially critically ill patients; if not treated properly, it can have harmful effects. Critical illnesses are usually painful, both because of the underlying source of the disease and the necessary procedures performed to monitor and care for these patients. Pain induces anxiety, sleep deprivation, disorientation, agitation, delirium, and often become chronic depression. Psychological factors (sleep deprivation, anxiety, and delirium) can also increase the perception of pain. Pain assessment is required for proper pain management. Opioids are commonly used in pain management, but acetaminophen, dexmedetomidine, and gabapentin have more advantages. The recent trend is multimodal analgesia, which uses a combination of analgesic drugs with different mechanisms of action. Another trend is the increasing use of pain relievers, which can control pain and relieve anxiety.