The lesion is characterized by glomerular thylakoid hyperplasia, and IgA deposition in the thylakoid region is seen by immunofluorescence. Pathologic changes: The extent of lesions varies widely. Early lesions are mild and focal, only a few glomeruli have mild thylakoid widening and segmental hyperplasia, and focal hyperplastic changes can develop into focal sclerosis. Some lesions are more pronounced and may have diffuse thylakoid hyperplasia and occasionally crescent formation. The most striking feature is the immunofluorescence showing lgA deposition in the thylakoid region and the concurrent presence of C3, lgG, etc. Electron microscopy confirms the deposition of electron dense material in the thylakoid region. Clinicopathological associations: The main symptom is microscopic or visual recurrent hematuria, which may be accompanied by mild proteinuria. A small number of patients present with nephrotic syndrome and renal insufficiency. IgA nephropathy is mostly a chronic progressive process, and about half of the patients have progressive lesions that can lead to chronic renal insufficiency. IgA nephropathy is a group of glomerular diseases with the same immunopathological features caused by multiple etiologies. Clinically, about 40% to 45% of patients present with carnal or microscopic hematuria, 35% to 40% present with microscopic hematuria with proteinuria, and the rest present with nephrotic syndrome and renal insufficiency. IgA nephropathy nephropathy is a common glomerular disease worldwide, and the prevalence of IgA nephropathy varies greatly across continents, countries, or in different regions of a country, such as Japan and Singapore in Asia, where the incidence of IgA nephropathy nephropathy accounts for 40-50% of primary glomerular disease, while the low incidence of Indian areas in the western United States accounts for only 2%. In general, the incidence is significantly higher in whites and yellows than in blacks. The incidence of IgA nephropathy in China accounts for 26% to 34% of primary glomerular disease. The ratio of men to women is about 2:1. Because the pathological types of IgA nephropathy and the degree of glomerular damage vary greatly, I personally believe that it is a collective name for a variety of diseases, but the current level of medical care is difficult to subdivide them. Therefore, patients should be closely observed for the frequency of the episodes of carnal hematuria, the degree of proteinuria, the presence of hypertension and the degree of impaired renal function, and the corresponding prevention and treatment measures should be taken respectively.