Renal tubular interstitial nephritis is mainly characterized by oliguria, proteinuria, low back pain and fatigue. It includes acute interstitial nephritis and chronic interstitial nephritis. 1.Acute interstitial nephritis: (1) Acute allergic interstitial nephritis: usually due to renal injury after medication, patients may show symptoms such as oliguria, low back pain, fever and arthralgia. (2) Infection-related acute interstitial nephritis: usually caused by bacterial, viral or parasitic infections of the kidneys, patients mainly show symptoms such as chills, high fever, low back pain, bacterial endocarditis and other symptoms, as well as symptoms of kidney damage such as proteinuria and microscopic hematuria. (3) Idiopathic acute interstitial nephritis: it is usually caused by acute kidney injury. The common symptoms of patients include hematuria, proteinuria, malaise, anorexia, nausea, myalgia, weight loss and so on. 2. Chronic interstitial nephritis: due to drugs or toxins, etc. In the early stage, patients have insidious onset of disease or only have non-specific extra-renal manifestations, such as fatigue, appetite loss, weight loss, dyspepsia, etc. As the disease progresses, patients may develop nocturnal and nocturnal symptoms, which are often caused by acute renal injury. As the disease progresses, patients may develop symptoms such as increased nocturia, mild to moderate proteinuria, and severe anemia. Tubulointerstitial nephritis may also have other symptoms, and it is recommended that patients go to regular hospitals in time and standardize treatment under the guidance of doctors.