High blood pressure puts stress on blood vessel walls. Over time, this can cause the arteries leading to the kidneys to narrow (renal artery stenosis) and harden. This reduces blood flow to the kidneys. Without sufficient blood and oxygen, the kidneys can't function properly. This damage to the renal arteries impairs the kidneys' ability to filter waste from the blood. It also hinders their ability to regulate crucial bodily functions, such as fluid balance and blood pressure.
The kidney's filtering units are called nephrons. Each kidney contains about 1 million of these units, each comprising a glomerulus and a tubule. Nephrons cleanse the blood by removing waste products, excess fluids, and toxins. High blood pressure can damage the blood vessels within nephrons, reducing their filtering efficiency.
When nephrons are damaged, waste and fluid build up in the body, causing swelling and other health issues. This damage also lowers the glomerular filtration rate (GFR), the key measure of kidney function. A reduced GFR indicates that the kidneys aren't filtering blood effectively, potentially leading to chronic kidney disease (CKD).
Healthy kidneys retain essential proteins in the blood while filtering out waste. High blood pressure can harm the filtering structures known as glomeruli, causing protein to leak into the urine (proteinuria).
Proteinuria is a warning sign of kidney damage. Untreated, it can weaken kidney function and accelerate kidney disease progression. Early detection of protein in the urine can help individuals manage their blood pressure and protect their kidneys from further damage.
Prolonged high blood pressure is a leading cause of chronic kidney disease (CKD). CKD is a long-term condition where the kidneys gradually lose their ability to function normally. As kidney damage worsens, waste builds up in the body, leading to serious health problems and even kidney failure. Regular blood pressure checks and kidney function tests can facilitate early detection and treatment.
High blood pressure fuels kidney damage, and vice-versa. Kidneys damaged by high blood pressure can't effectively remove excess salt and water. This causes fluid buildup in the body, further increasing blood pressure. Damaged kidneys may also release hormones like renin that constrict blood vessels, raising blood pressure. This creates a vicious cycle: high blood pressure damages the kidneys, and the damaged kidneys further elevate blood pressure. Untreated, this can lead to declining kidney function and other serious health problems, including heart issues.
Bao Bao (Times of India)
