“If the pain is meant to protect me, why does it have to be so unpleasant?” It’s one of the most important questions we can ask. Most people think of pain as something that happens to them. In reality, pain is something your body does for you. It is one of the oldest survival mechanisms we possess. To understand chronic pain, we first need to understand why pain exists at all.

Imagine you’re living 100,000 years ago…

You’re out hunting. Suddenly, a sabre-toothed tiger attacks. Somehow, you escape. But you’ve been badly injured. Your leg is gashed. You can barely walk. Now ask yourself: what does your body need you to do next? It doesn’t want you chasing another tiger. It doesn’t want you climbing mountains. It certainly doesn’t want you wandering miles in search of food. It wants one thing: to get you back to the safety of your cave, to stay there, to rest, to heal. Pain evolved to make sure you did exactly that.

Pain changes behaviour

Pain isn’t simply a sensation. It’s a survival strategy. If injuries weren’t painful, our ancestors would have carried on hunting, fighting and exploring despite serious injuries. Many would have bled to death or suffered even greater harm. Evolution found a remarkably effective solution. It made pain unpleasant. Very unpleasant. Pain changes how we behave. It makes us limp, protect an injured arm, rest, move differently, sleep poorly and pay attention to the injury. It also changes our emotions and our behaviour around other people. We may become quieter, withdrawn, irritable, anxious or low in mood. Activities that once brought us joy can suddenly feel overwhelming. That isn’t because we have become lazy, weak or unfriendly. It is because the nervous system is trying to protect us.

Pain is protection

Pain is your body’s way of saying: “Something isn’t right. Please pay attention.” Most of the time, it gets this exactly right. You step on a drawing pin and immediately lift your foot. You touch a hot pan and pull your hand away before you’ve even had time to think. Pain has protected you thousands of times throughout your life. Most of the time, you barely notice.

But what happens when the tiger has gone?