Linda entered the treatment room, distraught.

When I asked her what was wrong, she shared that another healthcare provider explained that there was nothing wrong with her shoulder; her pain was “in her brain.”

“Am I going crazy?”, she asked.

She felt dismissed and confused.

I assured her that her pain was as real as it felt.

But as we spoke further, it became clear that despite its blunt force, the practitioner’s statement contained a grain of truth.

While pain is usually triggered by a physical injury – a stubbed toe or sprained ankle, for instance – context, emotions, and expectations adjust the "volume" on the experience.

How else can we explain an athlete finishing a championship game with a broken foot, only to feel excruciating pain at the final whistle?

Why can a soldier who has lost a limb in battle often report feeling almost nothing until the emergency resolves?

A study on pain in Mainz

Linda posed the obvious question:

How precisely do thoughts influence pain?

To scratch the surface of this question, let’s explore a study conducted in Mainz, Germany [1]. 

Imagine you’re a participant.

You enter a laboratory, and a researcher pokes you with a hot (118 degrees Fahrenheit) rod five times in a row.

They then ask you to rate your pain on a scale of 0 (no pain) to 100 (maximal imaginable pain).

You respond, leave, and return for another round of torture for the next eight days.

Here’s the clever part. The researchers split participants into groups:

They tell group one that over the eight days, pain will decrease.

If pain was a purely physical sensation, independent of expectation, both groups’ scores should be identical.

Your brain dictates your level of pain

Their findings showed precisely the opposite.

When people were told the pain would decrease over time, their pain scores dropped by more than 50%.

When people were told the pain would increase over time, it did just that.

Amazingly, how much it hurts to be stabbed with a scalding hot poker largely depends on how much you expect it to hurt.

These results were no fluke.

In a similar study, researchers delivered electric shocks to participants' ankles with their feet submerged in cold water.

They asked them how much it hurt, and measured pain receptor activity in the spine.

Here’s the twist:

They told half the participants the cold water would dampen the pain and told the other half the cold water would intensify it.

The group primed to believe cold water was a painkiller reported 77% less pain and exhibited less spinal pain receptor activity than the second group [2].

Pain is an output from the brain, not an input from the body.

While no one’s pain is all in their brain, everyone’s aches and pains are powerfully influenced by expectations and circumstance.

Simply expecting pain to escalate – or dwindle – majorly influences whether it does.

A positive mindset is not a magic bullet, but it goes a long way.

Video: An illuminating Ted Talk on the foundational principles of pain science.

References

[1] Doganci, B., Breimhorst, M., Hondrich, M., Rodriguez-Raecke, R., May, A., & Birklein, F. (2011). Expectations modulate long-term heat pain habituation. European Journal of Pain, 15(4), 384-388.

[2] Goffaux, P., Redmond, W. J., Rainville, P., & Marchand, S. (2007). Descending analgesia–when the spine echoes what the brain expects. Pain, 130(1-2), 137-143.