Back pain with increased nocturia can be seen in many diseases. First of all, infections of the urinary system, such as pyelonephritis, when there are foci of infection in the renal pelvis of the patient, and the pathogens are usually upstream infections of Escherichia coli and Aspergillus, but also bloodstream infections of Staphylococcus and Streptococcus. Due to the stimulation of the infection, the mucosal vessels of the renal pelvis can become congested and dilated, and the production of inflammatory mediators can increase, which can stimulate the peripheral nerve endings and cause lumbar distension and pain. Secondly, it can be seen in men with benign prostatic hyperplasia and women with primary bladder outlet obstruction, mainly because such diseases tend to lead to poor urination, increased bladder residual urine, and reduced effective bladder capacity, and therefore are prone to frequent urination at night. Over time, the high pressure in the bladder also tends to cause ureteral reflux, leading to hydronephrosis which causes tension in the renal envelope, and thus a dull painful sensation in the lower back can occur. Finally, ureteral stone obstruction can lead to hydronephrosis and cause lumbar pain, and the stones stimulate the mucosa of the lower ureter and surrounding nerves, causing frequent urination and nocturnal polyuria. The occurrence of lumbar pain and nocturnal polyuria, timely medical consultation to avoid delaying the condition.