Most of the low density foci with unclear border in the right kidney are pathologic causes, and the common causes are renal cysts, renal tumors, etc. Relevant treatments should be taken after the causes are clarified. 1. Renal cysts: the imaging manifestation of renal cysts is the appearance of irregular blisters around the kidneys, and there can be low density foci with unclear borders. Renal cysts are cystic lesions of the kidney caused by lesions or anatomical abnormalities of the renal tubules, and the occurrence of renal cysts has a certain relationship with heredity and the blockage of inflammation of the renal tubules. If the renal cyst is larger than 5cm, surgery is recommended. 2. Renal tumor: renal tumor is a tumor that occurs in the kidney area of the patient, and the image can be manifested as low-density foci with unclear edges. Kidney tumor may be related to smoking, obesity, dietary habits, occupational factors, long-term exposure to some silk, cotton, leather and other chemicals, and may also be related to genetic factors. Surgery is feasible according to the condition. If the examination of the right kidney has a low density foci of unclear border, it is recommended that patients go to the regular hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.