In the early stage of kidney disease, there may be symptoms such as backache, fatigue, loss of appetite and foamy urine. 1. Lumbar Soreness: Kidneys are located on both sides of retroperitoneal spine, when they are damaged, lumbar soreness can occur. 2. Weakness: In the early stage of kidney disease, blood creatinine is elevated, and electrolyte and acid-base balance disorders can occur, resulting in weakness. 3. Loss of appetite: In the early stage of kidney disease, edema of digestive tract may appear, and then loss of appetite, nausea, vomiting and so on. 4. Foamy urine: Foamy urine is easy to appear when there is protein in urine. Proteinuria can occur in asymptomatic proteinuria and nephrotic syndrome. Early symptoms of kidney disease are atypical, in addition to the above symptoms, there are symptoms such as increased nocturia, edema, etc., which are easy to be ignored, and it is recommended to consult a doctor in time to find out the cause of the discomfort and follow the doctor’s instructions.