A. Clinical symptoms of primary nephrotic syndrome 1. Massive proteinuria ≥ 3.5g/24 hours, more tens of grams/24 hours. 2, hypoalbuminemia: ≤30g/L. 3, edema of generalized, postural, and depressed nature with varying degrees. 4, Hyperlipoproteinemia. Pathophysiology Due to altered glomerular filtration membrane permeability, protein excursion increases and large amounts of proteinuria are formed. Glomerular filtration membrane permeability changes, in addition to pathological changes, are also related to changes in glomerular epithelial cell membrane surface charge. Normal membrane surface has salivary acid protein, which is negatively charged, while albumin molecules are negatively charged at PH7.4, which makes albumin less likely to be filtered because of homogeneous repulsion, and salivary acid protein is reduced in simple nephropathy. This leads to increased protein filtration. The large amount of proteinuria leads to hypoproteinemia, especially a decrease in albumin, which decreases the plasma colloid osmotic pressure, and water and electrolytes leak from inside and outside the blood vessels into the tissue interstitium, together with increased secretion of secondary aldosterone and increased secretion of antidiuretic hormone. The edema is further aggravated by the effect of factors such as decreased natriuretic factors. The main cause of hypercholesterolemia is due to increased hepatic compensatory synthesis and, to a lesser extent, decreased lipoprotein catabolism. There are several pathological types of the disease, among which the microscopic lesion type is the most common (about 80%); simple nephropathy mainly belongs to this type, followed by focal segmental glomerulosclerosis and membranoproliferative nephritis. A small number of thylakoid proliferative type or membranous nephropathy, such lesions are mostly manifested as nephritic nephropathy. Second, the diagnosis of primary nephrotic syndrome is based on 1, high edema. 2. 24-hour proteinuria >3.5g. 3. Hyperlipidemia (cholesterol, triglycerides, phospholipids). 4.Low proteinemia. 5, except secondary nephrotic syndrome.