In the diagnosis of malarial nephropathy, the urine examination can be seen to be saucy red or soy sauce colored, and in some patients who have not been cured for a long time, nephrotic syndrome may appear. So what is the cause of the onset of urine saucy red or soy sauce color? The following is a brief introduction for you. Causes of red or soy sauce-colored urine Humans are generally susceptible to several species of human malaria parasites. Plasmodium infection is the only causative agent of the disease. It has been found that the incidence of kidney disease is much higher in malaria endemic areas than in non-endemic areas during the same period of time. In recent years, clinical and histological studies have revealed the presence of Plasmodium antigenic material in the immune complexes of patients’ glomeruli, further confirming malaria as an important etiological factor in the development of nephropathy. Chronic progressive renal damage caused by malaria can also be detected in the kidney tissue, and in the 1960s it was confirmed that the renal damage was due to an abnormal immune response induced by Plasmodium infection, resulting in immune complex nephritis. In recent years, it is believed that Plasmodium vivax nephropathy may be an autoimmune reaction, and the early stage is due to the formation of immune complexes from circulating Plasmodium vivax antigens, or due to the implantation of antigens into the capillary walls of kidney tubules, which combined with antibodies to form immune complexes in situ, resulting in the initial damage to the kidney, and then the damaged kidney tissue proteins can be used as autoantigens to promote the generation of autoantibodies, which then causes immune complex nephritis. There is a cross-immune reaction between serum antinuclear antibodies and Plasmodium vivax antinuclear antibodies in residents of Plasmodium triserium endemic areas. Patients are advised to go to the hospital for examination as soon as abnormalities are detected to avoid delaying the disease.