Urine yellow with fine foam may be physiological factors, urinary tract infections, kidney disease and other factors. 1. Physiological factors: drinking too little water for a long time or holding urine for a long time, resulting in urine concentration, so that the urine is yellow and fine foam, should increase the amount of water, to avoid holding urine for a long time, generally can be improved on their own, do not need to carry out other treatments. 2. Urinary tract infections: for example, cystitis, may be related to poor hygiene, it will make the urine yellow, fine foam, accompanied by frequent urination, urinary urgency, urinary pain and other symptoms, can be diagnosed by urine routine and urine culture and other tests. 3. Kidney disease: for example, glomerulonephritis, resulting in impaired function of the kidneys, will make the urine yellow with foamy urine, accompanied by swelling of the lower limbs and eyelids and other symptoms. Urine yellow with fine foam, and there are other abnormalities, may be the existence of disease factors, the causes are many, it is recommended that timely medical examination and treatment.