Why Kidneys Collapse Under Pressure

The relentless assault of high blood pressure can cause these tireless organs to fail forever. Read how kidney damage stays under the radar for decades.

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The two kidneys that flank the lower spine are exemplary organs. They are multitasking machines charged with controlling the body's fluid balance, filtering the blood of waste and producing a host of regulating hormones. They are not only at the center of the urinary system, but they also have a hand in making red blood cells and vitamin D. When they fail, the breakdown can have body-wide ramifications.

There are a number of underlying diseases can cause progressive kidney disease, chief among them is diabetes and high blood pressure. The effects of hypertension such as stroke, heart attack and heart failure may be more familiar. But high blood pressure assaults arteries everywhere, including in the kidneys, where it damages small blood vessels and filtering structures to the point of no return. Damage can occur under the radar, sometimes taking decades to make its presence known.

 

Kidney damage can be particularly problematic because ironically, among the many jobs the kidneys perform, is blood pressure control. If blood pressure sensors in the kidney malfunction, a vicious cycle of uncontrolled pressure ensues. Kidneys can slowly collapse, eventually progressing from mild chronic kidney disease to kidney failure or end-stage renal disease (ESRD), where they just stop doing any good at all.

It may take years before routine blood and urine tests give clues that the kidneys are beginning to fail. Eventually, as the damage worsens, people with kidney disease must have waste manually removed from their blood via dialysis or have a kidney transplant to sustain life.

Anyone with higher then normal blood pressure is at risk of developing kidney failure, particularly African Americans, who tend develop kidney disease even when blood pressure is only slightly elevated.

The Lowdown on High Blood Pressure

To help understand the concept of high blood pressure picture a water pipe: If the pipe becomes narrowed, or if the amount of water rushing through it is too great, pressure against the pipe wall is increased and eventually the pipe is compromised. It is the same in the body: The relentless pressure damages the blood vessels and the organs that rely on them.

In a healthy adult, blood pressure should hover around 120/80. Doctors focus on these two numbers because any deviation sounds an alarm, particularly when it gets too high. When blood pressure exceeds 120-139/80-89 it is called pre-hypertension and anything over 140/90 is hypertension.

Blood pressure is measured in mm of mercury (mmHg); the top number (systolic) refers to the force against the wall when the heart is contracting, and the bottom number is the pressure when it relaxes (diastolic). [You can remember it this way; systolic is closer to the sky and diastolic is closer to dirt.]

 

Kidney Preservation

To protect the kidneys from kidney failure, people with any level of hypertension must gain control and that may require a long-term, multi-pronged approach of lifestyle changes and medication. Strict adherence to a healthy diet, vigilant surveillance of blood pressure, and attentiveness to prescribed blood pressure treatments is essential. Anything less can mean a lifetime of dialysis or the need for kidney transplantation. Reducing blood pressure points early and consistently can help preserve your kidneys and your life.

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  • Follow the Dash Diet – The DASH diet is a special diet that promotes consumption of fruits and vegetables (9 servings a day) and low-fat dairy products (2 servings a day), over red meat, saturated fat, sweets and sugary beverages. Adopting this diet can help cut off up to 15 points.
  • Limit Salt Intake – Reducing dietary sodium to less than 2400 mg sodium a day can drive your blood pressure down 8 points, especially if you are a salt-sensitive person. You will need to be a bit of a label sleuth because salt can hide in many canned, fast and processed foods. Learn more about the Dr. Oz Salt Challenge here.
  • Exercise on Most Days – Performing at least 30 minutes aerobic physical activity per day can help you drop up to 9 points.
  • Drink Less Alcohol – Excess alcohol intake can tax the kidneys. Men should drink less than 2 drinks per day and women (and lighter-weight men) just 1 drink per day (a drink is 12 oz beer, 5 oz wine or 1.5 oz 80-proof whiskey). Keeping within these limits can reduce blood pressure by 4 points.
  • Normalize Body Weight – Keeping your body mass index less than 30 can lower blood pressure enough to pull you out of the danger zone. If you are overweight and lose 20 lbs, you can reduce your blood pressure by 20 points! Even a modest weight loss trims points.
  • Relax and Breath – Listening to classical music, meditating and practicing slowed breathing like Qigong can lower blood pressure by a few points.
  • Take Prescribed Medications – There are many types of medications to reduce blood pressure. Follow the advice of your doctor and take any prescribed medications as directed, even if you feel fine. High blood pressure can exist without symptoms so you may not know when you are spiking.
  • Perform Self-Checks Regularly – You can do this with an at-home blood pressure measurement device or machine at your local pharmacy.
  • Get Routine Examinations – Keep your scheduled appointment with your doctor for a periodic pressure check or to discuss any issues you may have with your medication. There are many medications to choose from if you are experiencing side effects or if your current medication isn't producing the best result.
  • Control Other Risk Factors – Control cholesterol, diabetes and sleep apnea, all of which also contribute to high blood pressure.