I'm not a physician. Last summer I noticed diminished sensation/numbness on my left side, mostly lower leg/foot and lower arm/hand. MRIs and x-rays of my neck, lower back, and brain showed herniated cervical (neck) and lumbar (lower back) discs but no cause for the diminished sensation/numbness. I became so aware of the condition, and lack of a cause, that it distracted me throughout the day and night. In early January I decided for myself that walking would be the best "treatment" -- I was athletic but spent many hours at a desk.
I stopped noticing the numbness before I reached Roncesvalles, and due to an unrelated camino injury finished the last 120 kilometers to Santiago on crutches.
I have been back home now for about a month and am aware of the numbness but no longer distracted or concerned because I was able to walk my camino and return in better health than when I left.
The camino for me was a powerful religious experience but I don't believe the Way bestows magical healing power on pilgrims. I do believe it can help pilgrims achieve goals they otherwise might not achieve, in mind and body.
My advice, for what's its worth as a non-physician, is to consult a doctor to rule out a detectable or serious illness or injury, and in the absence of such resume training with the hope to make your camino this summer.
(By the way, I found that ibuprofen relieved the sort of pain you describe and a host of other pains one encounters on the camino.)
Be well and Buen Camino.
