Painkillers work systemically rather than targeting the location of pain. Different types operate through different mechanisms. Ibuprofen and aspirin block enzymes that produce inflammatory chemicals, reducing the signal generated at the injury site. Paracetamol works through mechanisms that are not fully understood but appear to affect pain processing in the central nervous system. Opioids bind to receptors in the brain and spinal cord that influence how pain signals are processed and experienced. None of them navigate to the source of pain. Pain is a signal the nervous system sends to the brain, and painkillers interrupt it at different points along that pathway.
Daniel opens the episode with the natural assumption that painkillers find their way to where it hurts. The correction opens a conversation about how pain works as a signal, how different painkillers interfere with that signal, and what the brain’s role in experiencing pain actually is.
DanielMom, earlier when I had that headache, you gave me Advil and it went away. But how did the Advil know to go to my head? Like, how did it find the headache?
MomDaniel, here's the thing. It didn't.
DanielReally? What do you mean it didn't?
MomThe Advil went everywhere. Your whole body. All at once. The headache just happened to be where the problem was.
DanielSo it didn't target anything?
MomNot at all. You swallow it. It dissolves in your stomach, gets absorbed into your bloodstream, and from there, your bloodstream carries it all around your body.
DanielSo my feet got Advil too?
MomYes, your feet got Advil too. Your elbows, your fingernails, everything. Your body doesn't know where the medicine is needed. It just lets the bloodstream deliver it everywhere.
DanielSo, what was creating the pain signals?
MomSo, when your body is injured or inflamed, it often releases chemicals called prostaglandins. They're like alarm messengers. They help create inflammation, make nerves more sensitive to pain, and can contribute to fever.
DanielSo prostaglandins are basically your body's way of saying, something is wrong here.
MomExactly. And they are useful. Pain is information. It is your body's alarm system telling you to pay attention to something.
DanielSo what does Advil actually do?
MomIt blocks an enzyme your body uses to make prostaglandins. When that enzyme is blocked, your body makes far fewer prostaglandins. And with fewer prostaglandins, the nerves in that area calm down. The sensitivity drops, and the pain signal gets quieter.
DanielSo Advil doesn't actually take the pain away. It just turns down the volume on the alarm.
MomThat is exactly right. It usually doesn't fix what caused the pain. It reduces the chemical that was making your nerves more sensitive to it.
DanielIs that why it takes a while to work? Like it wasn't instant?
MomRight. Because the pill has to dissolve in your stomach first. Then get absorbed into your bloodstream. Then circulate through your whole body. Once enough ibuprofen has reached your bloodstream and started blocking the enzyme, the production of prostaglandins slows down, and the pain begins to ease.
DanielSo the 20 or 30 minutes is just travel and build-up time?
MomYes. And the same drug works for a sore knee, a fever, a toothache, cramps, all different problems in different places. And the same prostaglandins also help raise your body's temperature during a fever. So blocking them can help bring a fever down, too.
DanielSo it is the same mechanism. One drug, one target. Multiple problems solved.
MomBecause they all involve prostaglandins. One drug, one mechanism. Works wherever prostaglandins are part of the problem.
DanielBut wait! If prostaglandins are useful and pain is information, isn't it a bit weird to just switch off the alarm?
MomThat is a really thoughtful question. Prostaglandins do serve important purposes, including helping your stomach lining and supporting kidney function, which is one reason why these medications are taken as directed, with the right amount and with guidance, not just whenever you feel like it.
DanielSo like most things in the body, the same system that causes a problem is also doing useful things somewhere else.
MomAlmost always. Which is why medicine tries to do just enough, reduce the alarm that is causing unnecessary suffering, without completely shutting down a system that your body actually needs. So, Daniel, what is one thing you are taking with you today?
DanielOk, so, the Advil didn't find my headache, it went everywhere. What it actually did was block the enzyme my body uses to make prostaglandins, the chemicals that were making my nerves more sensitive to pain. Less prostaglandins, quieter alarm. And that is why it works for headaches, fevers, sore muscles, anything where prostaglandins are the problem.
MomTurns down the volume, doesn't fix the problem.
DanielNext time someone says Advil found their pain, I am correcting them.
