The initial symptoms of kidney disease are often hidden and difficult to find. This requires us to do regular physical examinations, especially urine tests. If the following 4 signs appear, it is likely that kidney function has been damaged. Signs of impaired renal function. Early detection of 4 signals 1. When the eyelid and lower extremity edema and renal insufficiency, the metabolic capacity for sodium is reduced, which easily leads to the retention of water and sodium metabolism. Excess water accumulates in the subcutaneous tissues, and symptoms such as eyelid edema in the morning and edema of the lower limbs after fatigue can appear. Press and hold the skin of the ankle with your hand. If you press one pit and the elasticity is very poor, it is usually edema. 2. Proteinuria and hematuria When the kidney is damaged, the ability to recover protein is reduced, which makes protein easily appear in urine. People who already have kidney disease also need to regularly test urine protein levels to assess kidney function. If inflammation, stones, tumors or blood vessels rupture in the kidneys, red blood cells will be excreted in the urine to form hematuria. Some foods or medicines may also cause urine to turn red, which is pseudo-hematuria, so it cannot be judged by urine color alone, and a urine test is required. Urine test is positive, the urine contains a lot of non-dissipating foam, which is proteinuria. If the number of red blood cells in the urine exceeds the standard, it is hematuria. 3. Increased creatinine Creatinine is a product of muscle metabolism, which is mainly filtered through the glomeruli and excreted from the body. When the muscle is not consumed vigorously, the amount of creatinine produced by the human body is relatively constant. Urine creatinine is 7-18 mmol/d for men and 5.3-16 mmol/d for women; blood creatinine for men is 53-106 μmol/L for men and 44-97 μmol/L for women. Increased blood creatinine and urinary creatinine for unknown reasons may indicate impaired renal function. 4. Fatigue, weak waist and knees From the perspective of traditional Chinese medicine, the kidneys contain the body’s yang and energy. Chronic kidney disease can easily make the kidneys weak, causing fatigue, weakness in the waist and legs, frequent nocturia, and cold limbs. It is also easy to affect the spleen and lungs, leading to phlegm and stasis, at the same time causing chest tightness, shortness of breath, loss of appetite, indigestion and so on.