Interoception

 What If the Patient Feels the Change Before the Monitor Can Measure It?

I have watched something happen with my son Alex for more than twenty years.

He knows.

Sometimes Alex knows something is changing inside his body before a monitor shows us anything unusual.

It has happened too many times, over too many years, for me to dismiss it.

And lately I’ve been wondering:

How close to the actual mechanism is Alex able to feel the change?

I don’t mean that he consciously thinks, My CO₂ is changing, my blood pressure is about to fall, or this particular physiologic pathway has just been disrupted.

I mean something more fundamental.

Maybe he is sensing the earliest downstream effects of a physiologic change, while our equipment is waiting for that change to become large enough to appear in the variable it measures.

Because a monitor and a human nervous system aren’t necessarily measuring the same thing.

• A pulse oximeter measures oxygen saturation.
• A blood-pressure cuff measures pressure at that particular moment.
• A ventilator measures certain aspects of breathing.
• A laboratory test measures what was present in a blood sample at the moment it was drawn.

But Alex is inside the system.

His nervous system is receiving information from his body continuously.

And although his spinal cord and brainstem injuries profoundly altered those pathways, altered does not necessarily mean absent.

Over the years, I’ve watched him recognize subtle changes involving breathing, bladder and bowel function, autonomic dysreflexia and other internal changes before the numbers necessarily explained what he was feeling.

During one hospitalization, his chest-tube drainage system inadvertently remained closed.

Alex felt that something was wrong.

His body reacted dramatically with autonomic dysreflexia. The monitors and imaging could tell us pieces of what was happening, but Alex had already detected that something inside him had changed.

That raises an important question:

What if Alex and the monitor are detecting different stages of the same event?

Maybe the monitor eventually detects the consequence.

Alex may be sensing something closer to the beginning.

There is a word that belongs in this conversation: interoception.

Interoception is our nervous system’s ability to sense what is happening inside our bodies—breathing, heartbeat, temperature, visceral stretch and other internal physiologic signals.

Most of us barely notice much of that information.

But imagine living for more than twenty years in a body where small internal changes can become enormous ones.

Imagine experiencing those patterns again and again.

Alex may have developed an extraordinary ability to recognize:

“I know this feeling. Something is changing.”

That is not mystical.

It could represent preserved internal sensory information, altered autonomic processing, unusually heightened awareness of internal changes, and more than two decades of learned pattern recognition.

I cannot prove exactly what pathway Alex is sensing.

But I can tell you what I have observed.

When Alex says something is changing, we listen.

We don’t wait for the monitor to give us permission to believe him.

We look.

We troubleshoot.

We ask what changed.

Because sometimes the machine hasn’t caught up yet.

And that leads to a larger lesson for medically complex care:

Patient awareness is clinical data.

It shouldn’t replace objective monitoring.

But objective monitoring shouldn’t replace the patient, either.

Especially when that patient has spent decades learning a body that medicine encounters only occasionally.

Perhaps the question shouldn’t always be:

“What does the monitor say?”

Sometimes it should also be:

“Alex, what are you feeling?”

Because the person living inside the physiology may sometimes detect the disturbance before we can measure its consequences.

Baseline is not just a number.

And sometimes, neither is the earliest warning.