The three physiological causes of pain are nociception (caused by actual or potential tissue injury), inflammatory pain (caused by inflammatory processes) and neuropathic pain (caused by nerve damage). Pain observations are an attempt to overcome various problems. The conscious nature of the cortex allows for the individual to make decisions and to act on the pain. The synapses conveniently divide the pain pathways into three main parts: the pathway from the periphery to the spinal cord, the pathway to the thalamus and the pathway to the sensory area of the cerebral cortex. Sometimes recognising pain in children is not easy, especially in babies and young children. There are some clues that can suggest the child is in pain. Opium's use in pain management, and also for sedation and even recreation, has been important for many years. Morphine is a potent analgesic for the management of severe pain, but it does cause respiratory depression, nausea, vomiting and constipation as side effects.