Previous studies have shown that sympathetic nerves are related to certain types of pain,and this phenomenon is referred to as sympathetic-sensory coupling.Chronic pain resulting from nerve injury can be exacerbated by sympathetic stimulation or relieved by sympathetic inhibition.In the present study,the correlation between pain and sympathetic nerves was analyzed in patients with severe pain in lower limbs,as well as in a chronically compressed dorsal root ganglion(CCD)rat model(model of low back pain and sciatica).Patients with severe pain in the lower limbs underwent chemical lumbar sympathectomy(CLS),and the analgesic effects of CLS were compared with painkillers.Results demonstrated significantly relieved lower limb pain following CLS,and the analgesic effects of CLS were superior to those seen with painkillers.In the CCD rat model,dorsal root ganglion neuronal activity significantly increased as a result of electrical stimulation to the sympathetic nerves.These results suggest that sympathetic nerves are closely associated with pain,and sympathetic-sensory coupling is likely in lower limb pain in both patients and rat models of CCD. Previous studies have shown that sympathetic nerves are related to certain types of pain, and this phenomenon is referred to as sympathetic-sensory coupling. Chronic pain resulting from nerve injury can be exacerbated by sympathetic stimulation or relieved by sympathetic inhibition. In the present study, the correlation between pain and sympathetic nerves was analyzed in patients with severe pain in lower limbs, as well as in a chronically compressed dorsal root ganglion (CCD) rat model (model of low back pain and sciatica). Patients with severe pain in the lower limbs underwent chemical lumbar sympathectomy (CLS), and the analgesic effects of CLS were compared with painkillers. Resulting demonstrated significantly relieved lower limb pain following CLS, and the analgesic effects of CLS were superior to those seen with painkillers. in the CCD rat model, dorsal root ganglion neuronal activity increased increased as a result of electrical stimulation to the sympathetic nerves.These results suggest th at sympathetic nerves are closely associated with pain, and sympathetic-sensory coupling is likely in lower limb pain in both patients and rat models of CCD.