Bad kidney can cause high blood pressure. Bad kidney mainly refers to renal insufficiency, and there are two causes of bad kidney function, mainly including renal substantive causes and renal vascular causes. Substantial renal causes are nephritis and nephrotic syndrome. In addition to poor kidney function, nephrotic syndrome can also have other complications, such as hematuria, proteinuria, hypertension, and this blood pressure is higher and more stubborn. In this case, the main focus is on treating the original disease, and the blood pressure will drop naturally after the nephritis or nephrotic syndrome is controlled. Another kind of renal function is caused by renal vascular causes, because of the narrowing of renal arteries, such as the formation of fixed plaque, renal artery fibrosis, etc.. In this case, the main treatment is angioplasty, for example, renal artery stenting can be used to achieve the purpose of blood pressure control. Therefore, it is important to identify whether it is a substantial renal problem or a renal vascular problem when poor renal function or bad kidney causes hypertension, so as to further clarify the etiology of hypertension for the purpose of treatment.