Dihydrocodeine is an opioid painkiller that is prescribed for moderate to severe pain, such as after an operation or a serious injury. It works by blocking pain signals from the central nervous system and the brain. In cases where weaker painkillers like paracetamol, ibuprofen and aspirin have not worked, dihydrocodeine is also used for long-term pain management. However, due to its potential for addiction and dependence, it should only be used as directed by a medical professional and for the shortest possible time.