Increased rennin activity Is seen in-

Higher-than-normal levels may indicate: Kidneys trying to raise falling blood pressure. Kidneys trying to raise falling blood pressure due to reduced cardiac output. Excessive renin is being secreted by the kidneys. Renal vascular damage leading to reduced JGA perfusion Malignant nephrosclerosis as the name implies is a serious condition. The kidney demonstrates focal small hemorrhages, which are obscuring the coicomedullary junction here. This is often due to an accelerated phase of essential hypeension in which blood pressures are very high (such as 300/150 mm Hg) renin activity is very high Ref Davidson 23rd edition pg 460