How does a painkiller know where I hurt?

Answer

Dear Ann,

A painkiller doesn’t know where you hurt. It acts on substances in our body that cause you to feel pain; by switching off those substances, it ensures that we no longer feel pain.

Painkillers have multiple mechanisms of action. In the case of morphine, for example, this will be via a completely different mechanism than with aspirin or paracetamol (dafalgan). In the case of aspirin, the painkiller prevents the formation of prostaglandins. It’s those prost glandins that make us feel pain, so having less of them will reduce or eliminate the pain.

If you take aspirin for a headache, for example, not only the prostaglandins in your head will decrease. But since they caused problems there and not elsewhere on your body, you will only feel the effect at the height of your head.

Hopefully that was an answer to your question.

Stephanie Verschuere