Small patchy slightly dense shadow of left kidney, common causes are kidney stone, calcification of kidney, high density cyst of kidney, etc. Surgical treatment, medication and other measures need to be chosen according to different causes. 1. If the high-density shadow is a kidney stone, generally the stone is less than two centimeters does not need treatment, drink more pure water, more exercise can be. When the stone is larger than two centimeters and causes pain or urinary tract obstruction, surgery can be performed to remove the stone. 2. High-density shadow can be caused by renal calcification diseases, such as hyperparathyroidism or renal tuberculosis. The former usually requires surgical removal of the parathyroid glands, and the latter should be treated with anti-tuberculosis drugs such as isoniazid and rifampicin after culture of Mycobacterium tuberculosis to confirm the diagnosis. 3. In the case of renal high-density cysts, when the cysts are small, no treatment is usually needed. When the cysts are large and produce compression symptoms, interventional therapy can be performed under ultrasound localization to inactivate the cysts. When there is a small patchy and slightly dense shadow in the left kidney, you should go to the hospital in time, clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor.