Symptoms of urinary tract infection triggering nephritis include back pain and frothy urine. Urinary tract infections include pyelonephritis, cystitis and other diseases. If urinary tract infections are not treated thoroughly or the condition recurs, they become chronic inflammation, and chronic inflammation can affect the kidneys, involving the interstitium and glomeruli, thus causing interstitial nephritis, glomerulonephritis and other diseases. The common symptoms of urinary tract infection causing nephritis include back pain, frothy urine, red urine, weakness, poor nausea, swelling of both lower limbs, etc. The above symptoms are caused by inflammatory stimulation, so the patient has back pain. Inflammation affects glomerulus and interstitial kidney, causing glomerulosclerosis and interstitial inflammation. Patients have protein and red blood cells in the urine, and the decrease of albumin in the body causes hypoproteinemia, so they have swelling, foamy urine, red urine, and poor nasal function.