Curious Kids: How does pain medicine work in the body?

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

I want to understand how pain medicine like Panadol works in our body. – Freddie, age 6, Melbourne.

In short, pain medicine is able to block the processes that cause the feeling of pain. To understand why, we need to explain a bit more about how pain works.

Pain happens when electrical signals travel from the spot where you hurt yourself up your nerves, to the spinal cord and then up to the brain.

When the pain signal gets to the brain, it lets your brain know there’s a big problem happening so we can respond.

So when we feel pain from a burnt hand, we quickly remove it from a fire. Or if a dog bites us, the pain tells us to run away.

So even though pain hurts, pain is important. It can protect us from more injury. Feeling no pain at all is actually quite dangerous.

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But your question was about pain medicine like Panadol. Panadol is just one brand of medicine called paracetamol – there are a lot of different brands.

Inside our bodies, paracetamol is able to block the processes that cause the feeling of pain.

Paracetamol not only acts at the site of the pain (like your burnt hand or sore arm) but also in the brain where the pain is felt.

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At the place where pain starts, such as a sore throat, a burnt finger or a broken arm, a lot of chemicals are made and released. These chemicals make you feel pain and also make your body send more blood flowing to the painful area. This is why the painful area is often red and swollen.

The extra blood flowing to the area includes white blood cells – special parts of our blood that fight disease. These white blood cells bring important chemicals. One of these chemicals goes by the name of “prostaglandin”. It increases pain and inflammation (swelling).

Paracetamol, and also other pain medicines such as ibuprofen (you might know it as Nurofen), stop your body from making prostaglandins.

When you swallow some paracetamol, it dissolves in your tummy and most of it is absorbed into your blood. The paracetamol then travels around the body to reach both the painful spot and your brain, where it then starts to reduce the feeling of pain.

Paracetamol is very safe if the dose taken over 24 hours (that’s one day and one night) is kept below a maximum amount. It is very important not to take too much paracetamol, as it can be very dangerous if you take too much.

So make sure to never, ever take paracetamol without being sure that the dose has been checked by an adult who has read the instructions on the box. Otherwise you could take too much and get very sick or even die.

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