Urine, yellow and cloudy, may suggest several causes: first, it is usually seen in infections of the urinary system, such as acute cystitis and acute pyelonephritis. Due to the infection of pathogens the blood vessels of the renal pelvis and bladder mucosa are congested and a large number of white blood cells will leak out, forming pus cells after killing the pathogens. Therefore, the urine will be mixed with a large amount of purulent secretions, and the urine will be yellow and cloudy, which will be more obvious when the organism drinks less water. Secondly, it can also be seen in bilirubinuria, which is mainly associated with hepatobiliary diseases and diseases of the hematological system, such as hepatocellular jaundice and hemolytic jaundice. The former is usually due to a decrease in the ability of liver cells to process and excrete bilirubin, so that bound bilirubin can enter the bloodstream and be excreted into the renal tubules via the glomerulus, causing yellow, cloudy urine. The latter is mainly due to hemolysis, which leads to an increase in the amount of bilirubin produced in the body and the limited ability of the liver to process and excrete bilirubin, so the amount excreted in the urine will increase accordingly and the urine will be yellow and cloudy. Finally, high ambient temperature, more sweating, and usually drinking too little water cause concentrated urine, which also shows yellow and cloudy urine.