What can pain killers be used to treat?

Non-steroidal anti-inflammatory drugs (NSAIDS). Examples of NSAIDs include ibuprofen, diclofenac and naproxen. Aspirin is also an NSAID. However, it is mainly prescribed (in low doses) to help to keep the blood from clotting - for example, for people who have had a heart attack in the past.

Paracetamol.

Weak opioids and strong opioids (sometimes called opiates). Examples of weak opioids include codeine and dihydrocodeine. Examples of strong opioids include morphine, oxycodone, pethidine and tramadol. Many people who need strong opioids are in hospital.