Half back pain may be caused by trauma, lumbar muscle strain, pyelonephritis and other reasons. 1. Trauma: such as impact injury, sprain, fall from height, etc., resulting in lumbar spine injury or soft tissue injury in the lumbar region, which leads to the phenomenon of half back pain. 2. Lumbar muscle strain: it is a chronic injurious inflammation of the muscles and their attachment points of fascia or periosteum, which may be caused by overloading, poor posture in lumbar activities and so on. Due to the stimulation of inflammation, patients may have half of the back pain. 3. Pyelonephritis: It is an inflammatory reaction caused by infection of pathogenic bacteria through upward and bloodstream channels when the body’s defense function is low. Due to the stimulation of inflammation, patients can appear half of the phenomenon of back pain, and the degree of back pain varies, mostly dull pain or soreness. Half back pain can also be seen in kidney stones and other causes, it is recommended to go to the hospital in a timely manner, clear the cause of the disease and follow the doctor’s instructions for treatment, to avoid delaying the condition.