Proteinuria itself is usually difficult to observe through the naked eye. Sometimes it is seen as cloudy or frothy urine, more often with the corresponding symptoms of the associated disease. Typical symptoms are mostly haematuria, proteinuria, oedema and hypertension, and may also be accompanied by urinary abnormalities such as frequency, urgency, painful urination, incomplete urination and blood in the naked eye. Proteinuria is mostly caused by pathological factors and is more dangerous. It can often lead to lower limb oedema and in severe cases, critical illnesses such as kidney failure, so once the cause is identified, treatment of the primary disease should be actively pursued.