Hidden pain in the left kidney can be caused by urinary stones, urinary tract infections, cysts, tumors or non-kidney causes. The more common diseases that cause vague pain in unilateral kidney are urinary tract infection, urinary stones, and different diseases are often accompanied by other different symptoms. Most of the pain from urinary stones is more severe, and in addition to this, hematuria may occur. Patients with urinary tract infections may experience frequent, urgent and painful urination, and some may have fever and chills. In addition to larger cysts or tumors can also appear left kidney pain. Non-urinary diseases, such as lumbar muscle and soft tissue injuries can also cause vague pain in the kidney area. In order to make a clear diagnosis, it is recommended that patients go to the urology department or nephrology department, and undergo relevant examinations, such as routine urinalysis, renal function, urological ultrasound, etc., to clarify the cause of the disease and then follow the doctor’s instructions for targeted treatment.