Case Study: Full bladders and nerve pain

One thing I always have to appreciate about many types of nerve pain, is that when the right sign is there, you know exactly what is going on. I don't run across this specific situation very often, but when it does pop up, the signs are typically very specific and make great examples of deeper origins of pain than simple musculoskeletal mechanisms.

This last year I was treating an 18 year old patient who is a competitive runner, and their chief complaint is severe lumbar back pain. Enough running distance or intensity for them will lead to issues eventually, but almost immediately if digestive issues are present. On the more interesting side, and the real tell, is that it disrupts sleep where if often is at the highest pain most often around 4am, where he will get up to urinate and immediately feels MUCH better and can get back to sleep pretty easily.

This presentation; pain often at high lumbar, kidney, or diaphragm level, though sometimes we'll see irritation at a wider spectrum of the lumbar plexus at the same time and may get some pain multiple areas which may also be alleviated to some degree when less pressure is being put on the femoral nerve after urination; this points to mechanical irritation of the lumbar plexus by the kidney, the femoral nerve in particular.

I'm amazed in this case that all the psoas use in running doesn't irritate it sooner, but high-volume athletes will often have issues that they may not have had if they were less active, and through all that volume will get to some less common symptoms.

We will want to address multiple aspects of the lumbar plexus and femoral nerve, and track down WHY these issues have started in the first place, but if your patient is getting back pain, especially upper lumbar and ~kidney/diaphragm level pain, that is worst in the early morning and better after urinating...think kidney on femoral nerve. And then track down WHY this happened (which is a potentially much broader discussion).