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, vomiting, 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.
What Your Kidneys Do
- 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
Acute Kidney Problems
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 and 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
- Have complications during a pregnancy, such as eclampsia and pre-eclampsia
Chronic Kidney Disease
If 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, when it’s simpler to treat
Diabetes (types 1 and 2) and high blood pressure are the most common causes. In diabetes, blood sugar levels that are too high over time can harm your kidneys. And if you have high blood pressure, your kidneys may not work well because the high blood pressure creates wear and tear on your blood vessels, including those that go to your kidneys.
Other causes include:
- Immune system diseases, such as lupus. 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. This can lead to scarring as the infection heals. If it happens several times, it can lead to kidney damage.
- Inflammation in the tiny filters (glomeruli) within your kidneys. This can happen after a strep infection.
- Polycystic kidney disease, in which fluid-filled cysts form in your kidneys. It’s genetic.
- Defects present at birth that 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. Lead poisoning, long-term use of some medications such as 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.