Patients with chronic nephritis or chronic kidney disease are often combined with hypertension for the following reasons: i. The kidneys secrete many biologically active factors that affect blood pressure to regulate human blood volume. When chronic nephritis or kidney disease occurs, the kidneys secrete inflammatory factors that cause activation of the renin-angiotensin aldosterone system, causing vasoconstriction, resulting in water and sodium retention, which raises blood pressure; ii. Patients with chronic nephritis or chronic kidney disease will experience sclerosis of the small renal arteries and increased renal vascular resistance, causing an increase in blood pressure; iii. Patients with chronic nephritis will reflexively cause spasm of the small renal arteries due to metabolic reactions, causing an increase in blood pressure.