Poor renal function may not have obvious symptoms in the early stage, but may have multi-system complications in the later stage, mostly manifested as abnormalities in the cardiovascular system, respiratory system, nervous system, endocrine system, etc. The causes are mostly related to hypertension and uremic cardiomyopathy. 1. Cardiovascular system: with the deterioration of renal function, the prevalence of heart failure increases significantly, and its causes are mostly related to water and sodium retention, hypertension and uremic cardiomyopathy. When acute left heart failure occurs, dyspnea, inability to lie down, pulmonary edema and other symptoms may appear, but usually no obvious cyanosis. 2. Respiratory symptoms: shortness of breath and shortness of breath can occur in fluid overload or acidosis, and severe acidosis can lead to deep and long breath. Excessive fluid and cardiac insufficiency can cause pulmonary edema or pleural effusion. 3. Neurological complications: mainly reflected in the central nervous system disorders and peripheral neuritis. Convulsions, consciousness disorder, mental abnormality, numbness of limbs and so on can occur. 4. Endocrine system: including endocrine dysfunction of kidney itself, abnormal glucose tolerance and insulin resistance, hypothalamic-pituitary endocrine dysfunction, and peripheral endocrine gland dysfunction. Poor kidney function may also have other complications, such as digestive system, skeletal nervous system and other problems. Once bad kidney function is detected, it is recommended to consult a doctor in time to identify the cause and standardize the treatment under the guidance of a specialist.