Uremia is not an independent disease, but a clinical syndrome common to various advanced kidney diseases, and is the end stage of progressive chronic renal failure. In this stage, in addition to disorders of water and electrolyte metabolism and imbalance of acid-base balance, there are extensive systemic symptoms of toxicity in the digestive tract, heart, lungs, nerves, muscles, skin, blood, etc. due to the retention of metabolites in the body. The main clinical manifestations of uremia are: 1. Digestive system manifestations: mainly loss of appetite, epigastric fullness and pain, acid reflux, nausea, vomiting. It is the earliest and most common manifestation of uremia. In severe cases, there may be tongue inflammation, oral erosion, vomiting blood and blood in stool. 2, hematopoietic system performance: chronic renal failure patients have varying degrees of anemia, called renal anemia. In the late stage, there may be bleeding tendency, manifested as subcutaneous bleeding spots, petechiae, gum bleeding, epistaxis, and in severe cases, gastrointestinal hemorrhage may occur. 3. Cardiovascular system manifestations: Commonly, there is hypertension, called renal hypertension. Late stage may have uremic myocarditis, pericarditis, various cardiac arrhythmias and heart failure. It is the most common cause of death in uremia. 4, respiratory manifestations: there is acidosis, dyspnea in heart failure, and uremic bronchitis, pneumonia, pleurisy, etc. may appear in the late stage. 5, skin manifestations: can be manifested as pale, dry, itchy skin and “urea cream”. 6, skeletal system: due to disorders of calcium and phosphorus metabolism, can appear osteoporosis, bone softening or fibrous osteitis and painful pseudo-fractures. 7, neuropsychiatric symptoms: central manifestations include unresponsiveness, depression, irritability, excitement, convulsions, drowsiness and coma. Peripheral manifestations are the manifestations of peripheral nerve degeneration and other lesions, skin allergy, burning pain, limb weakness and activity disorders, etc. 8, endocrine function abnormalities can cause unstable blood sugar fluctuations, menstrual disorders, etc. In short, although uremia can have the above-mentioned systemic symptoms, but the clinical encounter of patients with chronic renal failure, the symptoms exhibited by each person is different, some appear a systemic symptoms, and some appear multiple systemic symptoms. Uremic symptoms can occur slowly and remain hidden for a long time without being detected. They are often detected during a physical examination or when they are complicated by other diseases such as fever. Chronic kidney disease due to various causes is prolonged, progressive, and slowly progresses to renal decompensation and failure. Clinically, it is divided into four stages: 1, renal function compensatory stage: when the glomerular filtration rate (GFR) is reduced to 35-50% of normal, the patient can still remain asymptomatic and the blood creatinine is normal; 2, early renal failure: GFR is only 20-35% of normal, blood creatinine is higher than normal but lower than 450цmol/l, with nocturia, weakness, edema, loss of appetite, nausea and mild anemia, and occasionally acidosis 3, renal failure stage: GFR is only 10-20% of normal, blood creatinine 450цmol/l to 707цmol/l, clinical symptoms are obvious, patients often have severe anemia, edema, hypertension, may have nausea, vomiting, metabolic acidosis, hypocalcemia and hyperphosphatemia, etc.; 4, uremic phase: that is, advanced renal failure, GFR less than 10ml/min; blood creatinine greater than 707цmol/l, with severe systemic toxic symptoms and much water storage in the body. It is characterized by severe edema, intractable hypertension, often accompanied by pleural fluid and ascites. It is dependent on dialysis therapy to maintain life. Most often life-threatening due to hyperkalemia or acidosis or severe anemia or anuria causing heart failure or pulmonary edema or cerebral edema. Common causes of uremia: The order of the most common diseases leading to uremia in China, in descending order, are: 1. Various types of primary chronic glomerulonephritis: the pathogenesis is related to immunity. The main manifestations are proteinuria, hematuria, hypertension, edema, etc. 2, obstructive nephropathy: various causes of urinary tract obstruction resulting in poor drainage of urine, such as kidney and ureteral stones, prostatic hypertrophy, or ureteral stenosis, etc. causing expansion of the renal pelvis and calyces, called hydronephrosis, compression of normal kidney tissue, resulting in renal failure. 3, diabetic nephropathy: this is the most common complication of diabetes, but also one of the main causes of death in diabetic patients, research data show that in the course of more than 15 years of type 1 diabetes patients 30% to 40% will occur diabetic nephropathy, in type 2 diabetes patients 25% occur diabetic nephropathy. 4, lupus nephritis: mostly seen in women of childbearing age, the main manifestations are fever and joint pain, skin erythema, etc., and proteinuria and hematuria appear when the kidneys are damaged. 5, hypertensive nephropathy: Severe hypertension can cause sclerosis of the small renal arteries, reduced renal blood flow, kidney function damage. 6, polycystic kidney: polycystic kidney is a congenital disorder, and there can be several patients in the same family with the disease. Pathological examination can be seen in the development of defective water-filled small capsules. The normal kidney tissue is compressed. The disease can be hidden for a long time, and it is not diagnosed as polycystic kidney until the kidney enlarges and obvious renal insufficiency appears after 40 to 50 years old. 7.Other: interstitial nephritis, renal vasculopathy, drug-related kidney damage, etc. Treatment of uremia: 1, general treatment: including high quality low protein diet, hypotension, correction of anemia and correction of various metabolic disorders; 2, replacement therapy: including hemodialysis, peritoneal dialysis, colonic dialysis, kidney transplantation, etc.