Double kidney ultrasound cannot check for nephritis. Kidney ultrasound observes the size, volume and morphology of the kidney, as well as the presence of occupancy, stones and tumors. For patients with kidney stones or with kidney failure, the diagnosis can be further assisted by double kidney ultrasound. However, for patients with nephritis, the main examination is through urine routine as well as kidney function and other related tests. For routine urine examination, patients with nephritis will show urine occult blood and urine protein in the routine urine examination. If chronic nephritis is prolonged, renal failure may occur, and blood tests for renal function will show elevated blood creatinine and urea nitrogen, and a decrease in endogenous creatinine clearance. Therefore, to evaluate whether there is nephritis, you can do urine routine, kidney function, endogenous creatinine clearance, 24hUP quantification and other related tests.