With anemia, gastrointestinal discomfort and high blood pressure, it is best to have a kidney function test. Once elderly people have symptoms such as fatigue and weakness, occasional nausea and vomiting, they basically go to gastroenterology first to see if there is something wrong with their stomach. If a gastroscopy is done and a stomach problem is ruled out, it may be time to go to a Chinese medicine department for tonicity. If this patient comes to me, I will let him go for laboratory tests to check the glomerular filtration rate, creatinine, urea nitrogen and uric acid to see if the “indigestion” is caused by chronic renal failure. Don’t think I am making a big deal out of it, because chronic renal failure is very easy to ignore. In China, hundreds of thousands of people enter renal failure every year, and it is the final outcome of chronic glomerulonephritis, diabetic nephropathy, gouty nephropathy, lupus nephritis, recurrent urinary tract infections and hypertensive kidney damage. There are few characteristic clinical manifestations in the early stage of renal failure, and most routine physical examinations currently do not include indicators that mark renal decompensation, such as glomerular filtration rate, creatinine, urea nitrogen and uric acid, making renal insufficiency difficult to be detected early. If a patient has pre-existing chronic kidney disease with symptoms such as indigestion, it is easier for doctors to consider renal insufficiency. However, a significant number of patients with chronic renal failure do not have a history of kidney disease and are often misdiagnosed with gastrointestinal disease when they present with weakness, easy fatigue, decreased mental and physical strength, and gastrointestinal symptoms. When debilitating symptoms and pale anemia symptoms are evident, they are often misdiagnosed as hematologic diseases. Some gouty nephritis is treated as rheumatoid arthritis. There are also chronic renal failure treated as hypertension for a long time. Therefore, patients with anemia, gastrointestinal discomfort and hypertension should be considered for the presence of renal failure to avoid misdiagnosis and omission, which delays the opportunity for early treatment. The early symptoms of renal failure are often general weakness, easy fatigue, poor spirit, increased blood pressure, dizziness, later appearing gastrointestinal symptoms, poor appetite, morning nausea, and even vomiting self-conscious mouth odor, such as urine odor. Later, pallor and anemia may gradually occur, accompanied by dizziness and palpitations, itching of the skin, abnormal sensation of the limbs, numbness of the hands and feet. In the late stage, symptoms of various systems such as cardiovascular, respiratory, hematological, digestive, neurological, endocrine, skeletal, etc., as well as disorders of water-electrolyte acid-base balance, etc., may appear.