Having a chronic disease can make it feel as if your life has spun out of control. But, knowledge really is power. The things we worry about when we don’t know what to expect can be far worse than what may really happen. Learning about your kidneys is a way to feel more in control of your life and health again. In this section, we will cover:
- What kidneys do
- Stages of CKD and symptoms
- Medicines you may take
- Steps you can take to protect your kidney function
- Common blood and urine tests, and what they mean
What Kidneys Do
The main job of kidneys is to help keep your body chemistry in balance all the time. To do this, kidneys:
- Make Urine. Your kidneys make urine to get rid of wastes and extra water. Wastes come from some foods, breaking down medicines, and even just moving your muscles.
- Balance Minerals. Your muscles, blood vessels, nerves, and bones need precise amounts of minerals in your blood all the time. Kidneys sense the levels of minerals in your blood. They hold onto what you need and send the rest to your bladder, as urine.
- Control Your Blood Pressure. Kidneys keep water and salt(s) in balance in your blood. And, they make an enzyme (renin) that helps your blood vessels tense up to raise your blood pressure if it drops too low. High blood pressure can harm kidneys and cause CKD. Or, CKD can cause high blood pressure. Like the chicken and the egg, it can be hard to tell which came first.
- Help You Make Red Blood Cells. Each cell in your body needs oxygen to live, and red blood cells bring it. If you have too few red blood cells (anemia), your kidneys send out a hormone (erythropoietin, or EPO). EPO tells your bone marrow to make more red blood cells. Kidneys that don’t work well make less EPO.
- Keep Your Bones Strong. You need the right level of calcium in your blood all the time to live. Your bones are a “storage bank” for calcium and phosphorus. When you need more blood calcium, the kidneys send out a hormone. Active vitamin D is a hormone that lets your gut absorb calcium from foods. If the hormone signal does not work, your body will pull calcium out of your bones, which can make them weak and more likely to break.
- Help Keep Acid and Base Balance in Your Body. The pH in your body is close to neutral, but may be a little alkaline, or base (7.38 to 7.42). A pH that is too high or too low can be fatal. Kidneys work with your lungs to keep the right pH level.
