Soreness in the lumbar fossa is commonly due to the following causes: first, lumbar dorsal fibrous tissue inflammation: the patient will have inflammation of the muscles and fascia of the lumbar back, which manifests as clinical symptoms of soreness at the lumbar fossa, which is especially obvious in the early stage, and after manipulation of the lumbar muscles and fascia, the soreness can be improved quickly. If treatment is delayed, it may also involve the nerves and cause numbness in the lower limbs. Second, urinary stones or pyelonephritis: can also induce clinical symptoms of lumbar fossa pain, the pain is usually not serious and does not affect the normal life of the patient. If treatment is delayed, the pain symptoms may worsen and can make the patient restless. Ultrasound examination can reveal the exact location of the lesion, and early diagnosis and early treatment can lead to significant relief of clinical symptoms.