context: Kidney disease can affect your body's ability to clean your blood, filter extra water out of your blood, and help control your blood pressure. It can also affect red blood cell production and vitamin D metabolism needed for bone health. You're born with two kidneys. They're on either side of your spine, just above your waist. When your kidneys are damaged, waste products and fluid can build up in your body. That can cause swelling in your ankles, nausea, weakness, poor sleep, and shortness of breath. Without treatment, the damage can get worse and your kidneys may eventually stop working. That's serious, and it can be life-threatening. Healthy kidneys: Keep a balance of water and minerals (such as sodium, potassium, and phosphorus) in your blood Remove waste from your blood after digestion, muscle activity, and exposure to chemicals or medications Make renin, which your body uses to help manage your blood pressure Make a chemical called erythropoietin, which prompts your body to make red blood cells Make an active form of vitamin D, needed for bone health and other things If your kidneys suddenly stop working, doctors call it acute kidney injury or acute renal failure. The main causes are: Not enough blood flow to the kidneys Direct damage to the kidneys themselves Urine backed up in the kidneys Those things can happen when you: Have a traumatic injury with blood loss, such as in a car wreck Are dehydrated or your muscle tissue breaks down, sending too much protein into your bloodstream Go into shock because you have a severe infection called sepsis Have an enlarged prostate that blocks your urine flow Take certain drugs or are around certain toxins that directly damage the kidney Have complications during a pregnancy, such as eclampsia and pre-eclampsia Autoimmune diseases, when your immune system attacks your body, can also cause an acute kidney injury. People with severe heart or liver failure commonly go into acute kidney injury, as well. When your kidneys don't work well for longer than 3 months, doctors call it chronic kidney disease. You may not have any symptoms in the early stages, but that's when it's simpler to treat. Diabetes (types 1 and 2) and high blood pressure are the most common culprits. High blood sugar levels over time can harm your kidneys. And high blood pressure creates wear and tear on your blood vessels, including those that go to your kidneys. Other conditions include: Immune system diseases ( If you have kidney disease due to lupus, your doctor will call it lupus nephritis.) Long-lasting viral illnesses, such as HIV/ AIDS, hepatitis B, and hepatitis C Pyelonephritis, a urinary tract infections within the kidneys, which can result in scarring as the infection heals. It can lead to kidney damage if it happens several times. Inflammation in the tiny filters (glomeruli) within your kidneys. This can happen after a strep infection. Polycystic kidney disease, a genetic condition where fluid-filled sacs form in your kidneys Defects present at birth can block the urinary tract or affect the kidneys. One of the most common ones involves a kind of valve between the bladder and urethra. A urologist can often do surgery to repair these problems, which may be found while the baby is still in the womb. Drugs and toxins, such as lead poisoning, long-term use of some medications including NSAIDs (nonsteroidal anti-inflammatory drugs) like ibuprofen and naproxen, and IV street drugs can permanently damage your kidneys. So can being around some types of chemicals over time.