How Hypertension Is Related To Kidney

High blood pressure or hypertension is one of the most characteristic phenomenon of chronic glomerulonephritis. It is evident that renal lesions (pathological abnormality in kidney) of an ischemic kidney (kidney with poor blood supply) may cause hypertension. This has been seen in the secondary hypertension which develops in the course of glomerulonephritis. Mechanical as well as pathological compression of renal parenchyma has been found to cause hypertension in experimental animals. Chronic pyelonephritis may also cause hypertension.

A variety of renal disorders (kidney diseases) may give rise to hypertension. The kidney disease may be parenchymal or of vascular origin primarily. Morbid anatomical studies have revealed that partial occluding of even one of the renal arteries due to intimal thickening (thickening of internal lining of artery) could be a cause of hypertension due to renal involvement. The vascular or presser substance can be formed by an ischemic kidney. Healthy kidneys are capable of eliminating any presser substance formed in the system. The circulating presser substance is called hypertensin or angiotonin. The angiotonin is formed in the blood by the interaction of an enzyme, renin, secreted by ischemic kidney. The maintenance of normal blood pressure depends on a correct balance between the production of a presser material by the adrenal cortex and its removal by the kidneys. The hypertension may be the result of over-activity of the adrenal gland or some renal disorder.

The primary hypertension and the renal hypertension could be ruled out by the family physician of the patient. In the primary hypertension, the high blood pressure develops early without any renal insufficiency, but in glomerulonephritis, the hypertension develops gradually with renal insufficiency and anemia (fall in hemoglobin level in blood). However, if the patient is seen only after the development of uremia (high level of urea in blood) making distinction between the primary or secondary hypertension could be difficult.