This kind of symptom may suggest some problems that would be better addressed by Western medical attention. Check in with your MD and if your pancreas and liver are okay, go visit your practitioner of Chinese medicine, we have some great answers for you. Basically, this is a back pain, normally in the lower back that is associated with a kind of infection in the urinary tract or other area in the lower abdomen. This might be kidney stones, this might be a bladder infection. This is often some uro-genital disorder that may include a local infection of some sort.
Herbal medicine is often times employed to dry the damp and clear the heat.
Herbal medicines again would be used to treat this condition, though the formula itself would be chosen based on other signs and symptoms. Like the damp heat problem listed above, this is not a nerve impingement syndrome but an issue that deals with the organs found beneath the skin in the lower back. Those are the kidneys. Kidney pathologies run the gambit from stones, to a deficiency of Yin or Yang in the body. Yin deficiency tends to include lower back ache that is a long term problem, six months minimum with no history of trauma.