Sore kidneys in the morning may be related to soft bed, kidney disease, lumbar spine disease and so on. 1. Soft bed: If the bed is too soft at night, it may lead to the body not getting complete rest, relaxation, spasm of lumbar muscles, etc., which will make the kidneys feel sore after waking up in the morning. 2. Kidney diseases: when patients suffer from kidney cysts, kidney stones, pyelonephritis and other diseases, it may lead to soreness in the kidneys in the morning. 3. Lumbar spine disease: If the patient has lumbar disc herniation, lumbar spine myofasciitis, lumbar muscle strain and other diseases, he/she will feel soreness in the kidneys when waking up in the morning. Patients who feel soreness in the kidneys in the morning should go to the hospital in time, and follow the doctor’s instructions for treatment after clarifying the cause of the disease.