Is it glomerular disease? Is it non-glomerular disease? Is the kidney function normal? (a) Glomerular disease Whether it is glomerular disease mainly depends on the presence of edema, granular tubularity, massive proteinuria, and glomerular hematuria. If it is a kidney disease: ① Any edema is a glomerular disease, but chronic pyelonephritis, chronic interstitial nephritis and other non-glomerular diseases can also appear edema in the late stage, indicating that it has been involved from the interstitial glomerular tubules to the glomeruli. Not all glomerular diseases can present with edema, e.g., edema is not present in asymptomatic proteinuria/hematuria (occult nephritis). Therefore, edema has low specificity and sensitivity in glomerular diseases. ②Granular tubular pattern: mostly seen in acute glomerulonephritis, occasionally in drug and heavy metal-induced interstitial nephritis. If there is granular tubular pattern and proteinuria ≥2.0g/d, definite glomerulopathy can be identified. ③Large amount of proteinuria, proteinuria 2.0g/d is mostly glomerular disease, if ≥3.5g/d, the possibility of glomerular disease is greater; if large amount of proteinuria, urine protein electrophoresis is non-selective, can be certain glomerular disease. (④Glomerular hematuria: urine with RBC tubular or urine RBC count above 8000/ml, morphology more than 75% is aberrant RBC,can be affirmed as glomerular disease. (B) Non-glomerular disease ①Tubular function is impaired earlier than glomerular: such as chronic interstitial nephritis, chronic pyelonephritis, before the glomerulus is impaired, the damage of tubular interstitial first appears, such as nocturia, low specific gravity urine, nephrogenic diabetes, nephrogenic amino acid urine. (2) Renal tubular proteinuria, urine protein quantification is usually <1.5g/24h,qualitative ±~+, urine protein disc electrophoresis for low molecular proteinuria, protein zone below albumin, i.e. molecular weight of 1~70,000, most protein molecular weight is 15,000~40,000. Lysozyme and β2-MG in the urine were increased. ③The two kidneys are unequal in size, such as chronic pyelonephritis, renal tuberculosis, renal artery stenosis, etc. Most of them show unilateral lesions, causing unilateral renal atrophy or uneven renal surface, which is definitely non-glomerular disease. ④Urinary tract infection, chronic pyelonephritis, renal tuberculosis itself is upper urinary tract infection, while obstructed kidney, reflux kidney, etc. mostly combined with urinary tract infection, if there is WBC or WBC tubular type in the urine, it is mostly non-glomerular disease. What syndrome? (a) Glomerular disease 1, acute glomerulonephritis syndrome: rapid onset, with hematuria, proteinuria, tubular urine; often with swelling and hypertension. 2, acute glomerulonephritis syndrome: rapid onset, rapid development, soon appear little or no urine; hematuria, proteinuria, tubular urine; may have swelling, hypertension is often mild. At the initial onset, it is quite similar to heavy acute glomerulonephritis, but it continues to develop rapidly, often with rapid onset and development of anemia and hypoproteinemia; renal function deteriorates rapidly, and uremia occurs within weeks to months. 3. Asymptomatic proteinuria and/or hematuria syndrome: no clinical manifestations such as edema, hypertension and azotemia, mainly mild to moderate proteinuria (<2.5 g/d) and/or hematuria. For proteinuria alone, tubular proteinuria should be excluded; simple hematuria must exclude hematuria caused by urinary tract infection, stones and tumors. 4, nephrotic syndrome: ① large amount of proteinuria (≥3.5g/d/1.73m2); ② hypoproteinemia (plasma albumin Q30g/L); ③ edema; ④ hyperlipidemia. 5, chronic glomerulonephritis syndrome: there is a longer history of edema, hypertension, urinary routine with proteinuria, tubular urine and a small amount of red blood cells; renal function is mildly impaired and progresses slowly, finally renal failure occurs. (B) Non-glomerular diseases 1. Interstitial tubular disease syndrome: ① mild proteinuria (<1.5g/d), increased urinary β2-MG. (ii) Leukocyturia and occasionally leukocyte tubular pattern. ③Tubular insufficiency, if accompanied by glomerular dysfunction, tubular dysfunction is early and severe. ④The kidney may have asymmetrical scar formation and calyx deformation, and some cases have a single case of renal atrophy. 2, frequent urination - urinary discomfort syndrome: the patient urinates more often, but the 24-hour urine volume does not increase, and some patients feel the feeling of urination again after urination. There is pain, burning or other discomfort during urination. 3.Kidney stone syndrome: history of renal colic or hematuria or discharge of small stones, and stones found by X-ray or ultrasound. 4, urinary tract obstruction syndrome: urinary retention can be found when the bladder is obstructed at the mouth. In upper urinary tract obstruction, ultrasound examination may reveal pelvic fluid. In acute obstruction, there may be little or no urine and azotemia. In chronic obstruction, polyuria, nocturia, lumbar pain, and enlarged renal shadow may be present. There may be hematuria, pusuria, and discomfort in urination. (C) Renal failure 1. Acute renal failure syndrome: Acute deterioration of renal function caused by various etiologies (daily rise in blood creatinine of 44.2umol/L or more). Most of them present with oliguria or anuria, proteinuria, hematuria, leukocyturia, tubular urine, and may have hypertension and edema. 2. Chronic renal failure syndrome: ① Azotemia for more than 3 months. ②Signs and symptoms of long-term renal failure, such as special face of chronic renal failure, anemia, skin urea cream, nocturia or oliguria or polyuria, edema, hypertension, etc. ③Bilateral kidneys may shrink. ④Tubular pattern of renal failure, proteinuria, hematuria may be present in the urine sediment. (⑤ Water and electrolyte imbalance. (iv) Judgment of renal function (Is renal function normal?) Acute renal failure is considered when there is a sudden and significant decrease in urine output caused by various etiologies and when renal function deteriorates sharply (blood creatinine rises 44.2umol/L per day) or more. Chronic renal failure is considered if, on the basis of various chronic renal parenchymal diseases, renal function slowly decreases, the glomerular filtration rate (GFR) is below 50% of normal, and the endogenous creatinine clearance rate is below 50 ml/min. On the basis of determining the presence of acute and chronic renal failure, glomerular disease and non-glomerular disease are then approached in the search for the cause. Underlying disease All of the above syndromes are a clinical syndrome and are not independent diseases. The diagnosis of primary disease can be established only if all secondary diseases are excluded. For example, in the case of acute glomerulonephritis syndrome, in the search for the underlying disease, lupus nephritis, purpura nephritis, mixed connective tissue disease, hepatitis B-associated nephritis, pulmonary hemorrhagic nephritis syndrome, multiple myeloma and other tumors with renal damage, infective endocarditis with renal damage, hereditary nephritis, etc. In the process of exclusion, if one of the above diseases is found and differentiated from similar diseases, the can be diagnosed. In order to diagnose primary acute glomerulonephritis, it is necessary to exclude the secondary diseases mentioned above.