Kidney stones can cause pain, hematuria, hydronephrosis, urinary tract infection, and in severe cases, may cause renal insufficiency or tumors. The hazards of kidney stones are as follows: 1. Pain: Smaller stones in the renal pelvis can cause smooth muscle spasm due to greater mobility and direct stimulation of the epithelium. When the stone is embedded in the junction of the renal pelvis and ureter, acute obstruction occurs and renal colic appears. The degree of renal colic is severe, with knife-like pain. Patients can be in pain until they are deflated. 2, hematuria: more hematuria occurs after an attack of renal colic, hematuria is due to damage to the renal pelvis and ureter by the rough surface of the stone, capillary rupture, causing bleeding. A small number of people can see red or wash water-like urine, most of them are microscopic hematuria, which is not visible to the naked eye. 3, hydronephrosis: chronic obstruction of kidney stones for too long causes hydronephrosis in the kidney, and pressure above the obstruction site leads to reduced blood flow to the kidney and decreased kidney function. 4, renal insufficiency: when the occurrence of double kidney stones or kidney stones in the only kidney, can cause renal insufficiency, serious cases reach the degree of uremia. 5, infection: combined with urinary tract infection will appear chills, high fever, nausea, vomiting and other symptoms, need to consider may be due to stone induced urinary tract infection, abscess kidney, infectious shock. 6, tumor: the stone itself and the chronic obstruction caused by the stone can stimulate the metastatic epithelial cells for a long time, which can lead to squamous epithelial cell metaplasia and even squamous epithelial cell carcinoma, that is, squamous carcinoma. The renal colic caused by the kidney stone itself is intense and affects the quality of life of patients. If left unattended for a long time, it may induce renal insufficiency and tumor with serious consequences. Therefore, it is necessary to pay attention to the timely diagnosis and treatment of kidney stones.