why does renal failure cause hypertension

Renal failure can lead to hypertension due to a variety of reasons. The kidneys are crucial in regulating the body's fluid and electrolyte balance. When kidney function is compromised, the excretion of water and sodium ions is reduced, resulting in increased blood volume and elevated blood pressure. Additionally, the kidneys synthesize and release a hormone called renin, which, through a series of reactions, leads to the formation of angiotensin II—a potent vasoconstrictor that can raise blood pressure. Furthermore, chronic kidney disease patients often experience inflammation and oxidative stress, which may contribute to hypertension by impacting vascular endothelial function and promoting arteriosclerosis.

To delve deeper, the hypertension caused by renal failure can be understood through several mechanisms. Firstly, with impaired kidney function, the kidneys' ability to excrete sodium diminishes, leading to sodium and water retention and an increase in blood volume, which is a direct cause of hypertension. Secondly, the decline in glomerular filtration rate means the kidneys cannot effectively clear waste and excess water from the blood, increasing blood osmotic pressure and stimulating the secretion of atrial natriuretic peptide, thus exacerbating sodium and water retention. Additionally, renal failure patients often suffer from anemia, and to compensate for hypoxia, the body increases cardiac output, raising blood pressure. Lastly, chronic kidney disease patients frequently have insulin resistance and deranged sugar metabolism, which may indirectly lead to hypertension by affecting the cardiovascular system.

For patients with renal failure and hypertension, it is important to maintain a low-salt diet, control fluid intake, engage in appropriate physical activity, and regularly monitor blood pressure and kidney function. Regarding pharmacological treatment, it is essential to select antihypertensive medications under a physician's guidance, avoiding drugs that could exacerbate kidney damage. Actively managing the underlying disease and improving lifestyle can aid in controlling blood pressure and slowing the progression of kidney function deterioration.