system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do painkillers work?

For example, if I have a headache, when I take a painkiller does it fix the problem that's causing my headache or does it just block the pain receptors and the problem remains? If the problem remains, wouldn't it be bad to take painkillers?
gpt
They block your pain reception. Some have other effects too that reduce inflammation for example.

In general that *can* be good, because your reaction to pain (stress, clenching) can make it worse.

But in general the cause stays, and painkillers are rarely a good longterm solution.