One pain at a time.

Right now, I’m experiencing excruciating pain from a small leg injury that has become infected (I’m seeing a doctor in the morning). But I also have a fair amount of chronic pain in both knees . . . pain that changes, but never goes away . . . until now. For the first time in years I am feeling no pain in my knees, unless I deliberately turn my legs certain ways.

The reason why my knees are pain-free is that my leg injury is hurting so much that my brain just focuses on that, and doesn’t even notice the pain from my knees. I have noticed this sort of thing before, that I can feel only one specific pain at a time. Even with my knees, it’s always been a matter of one knee hurting more than the other, and that’s the only one I really feel. Several years ago I had a bad toothache and also a cut on my hand, and I barely felt the cut.

Is this “one pain at a time” something everyone experiences? I can see how this can be a survival trait, to enable a person to focus on the greater pain, and tend to it. But what exactly is going on physiologically?

I’m no physiologist, but it appears there’s some sort of attention limit for the brain. I don’t think it’s limited to pain either. Any really strong or high priority sensation tends to make everything else much less noticeable.

I recall reading years ago in a book by Daniel C. Dennett that claimed that some pain blocking techniques are based on a variation of this. Supposedly if you concentrate enough on the source of a pain you can for a time block out the pain itself, apparently because all your attention is taken up by the nerves that transmit the details of the damage*, not the c-fibers that transmits the part of the sensation of pain that hurts.
*Ever stepped on something sharp, realized you were injured and only actually had your foot start to hurt a second later? That’s the two pain nerve systems in action; the c-fibers are cruder and transmit much more slowly; it takes about a second to feel the pain because it takes that long for the signal to reach your brain. The system that gives you detailed information about where you are damaged is much faster, but it doesn’t actually “hurt”; you just feel you are damaged.

It sounds like you may be describing the gate control theory of pain. As mentioned in the linked article, this is why it does help to shake your hand after hitting your thumb with a hammer. It also provides the underlying rationale for TENS (Transcutaneous Nerve Stimulation) treatment of chronic pain.

I recently fell down the atirs and broke my wrist, two toes, and my tailbone. The oly pain I felt was from the last one.


When my husband had a roadbike accident years ago, he had a small radius fracture near his elbow that caused a lot of pain. His arm was put in a temporary cast from wrist to above the elbow. It wasn’t until a week later and a check-up on that fracture that he discovered that his wrist was severely dislocated, eventually requiring surgery. Apparently the elbow fracture was painful enough to block any pain from lower down the arm. It was rather weird!

Is that the same phenomenon that is coming into play when capsaicin is used to manage chronic pain?