Lupus and Your Kidneys
As you may know, having “systemic” lupus means that the disease can harm almost any organ or tissue in your system—from your heart, to your brain, joints, and skin. But certain parts of your body are more likely than others to get damaged, and your kidneys are among them.
In a third of people with lupus, the immune system attacks the kidneys and causes more problems than any other part of this chronic disease—probably because these bean-shaped organs are so important, even though you can’t see them or feel them working.
Your two kidneys are about the size of your fists and are found near the middle of your back. They work incredibly hard at keeping the balance of fluids in your body at just the right levels, taking out waste and extra water from your blood and sending these out of the body through urine. The kidneys also help to control hormone levels and the amount of pressure in your blood vessels.
If lupus attacks the kidneys and gets in the way of them doing these important tasks, harmful toxins can start to build up in the blood and make you very sick.
Some people in this situation have to go on “kidney dialysis” to let a machine do the work that the kidneys can’t do. And in some cases, a kidney from another person—a kidney transplant—has to be put into the body to substitute for the one that stopped working.
But it’s much better to catch problems early on, before these complicated and expensive fixes are necessary. Some people actually have signs that something is wrong with their kidneys, such as needing to urinate much more (or less) than usual, or feeling unusually tired or itchy. They may lose their appetite, vomit a lot, develop pain in the lower back, have swelling in their hands or feet, or actually lose feeling in these areas. Tell your doctor right away if any of these things happen to you.
But because many people do not feel at all sick, even though their kidneys are being attacked, it’s important that everyone with lupus regularly have their kidneys checked through blood and urine tests. If a doctor detects a problem, she can do a small operation to take a tiny piece of the actual kidney to then look at it under a microscope. This is called a kidney biopsy.
So whether you have lupus kidney problems or not, it’s a good idea to keep these workhorses as healthy as possible by eating very little salt (less than 3 grams of sodium a day), lowering stress levels in your life, and keeping blood pressure under control. With careful care, the kidney and other “systems” can usually keep working in people with lupus.