When the Pain System Becomes More Sensitive

Pain is part of the body's protective system.

When something happens in the body, information travels through the nervous system to the spinal cord and brain.

The brain processes that information together with other things happening in the body.

The result can be pain.

Pain can make us react.

Pull our hand away from something hot.

Take weight off an injured foot.

Stop when something hurts.

In this way, pain can help protect us.

Pain and Injury Are Not Always the Same Thing

This is important.

How much pain you feel does not always tell you how serious an injury is.

A small injury can sometimes hurt a lot.

A serious injury may sometimes cause surprisingly little pain at first.

And with long-term pain, the pain can continue even after the original injury has healed.

Pain is more complicated than a simple signal coming from an injured part of the body.

When the System Becomes More Sensitive

With long-term pain, the way the nervous system responds to signals can change.

The system can become more sensitive.

Things that once caused only a small reaction may start to hurt more.

Pain may also be triggered more easily or last longer.

This is often called sensitisation. [1]

It does not mean the pain is imagined.

The pain is real.

What has changed is how the nervous system responds to and processes information.

Why Pain Can Be Different From Day to Day

Pain is not only affected by what is happening in one part of the body.

The whole situation can play a role.

For example:

  • sleep

  • stress and worry

  • movement and physical strain

  • recovery

  • illness and inflammation

  • previous experiences of pain

This is one reason the same body can feel very different from one day to another. [2]

A worse pain day does not necessarily mean that a new injury has occurred.

And a better day does not mean the pain you felt before was any less real.

Pain Is Real

When medical tests do not show a clear explanation for how much pain you are experiencing, it can be easy to start doubting yourself.

But pain does not have to show up on an X-ray to exist.

The nervous system is part of the body.

And when the way pain is processed changes, the experience of pain can change too.

Understanding this does not make the pain disappear.

But it can make it less difficult to understand.

Pain does not always mean that something new has been damaged.

Sometimes the body's pain system has become more sensitive.