Living with One Kidney? 5 Things to Know

Dr. Molina and Dan R.
With many types of kidney cancer, surgical removal of the cancerous part of the kidney is part of treatment. This is also known as a “nephrectomy.” Depending on the size and location of your tumor, you may have had all or part of the kidney removed. People only need one kidney, but it’s very important to protect your remaining kidney function since the kidneys are responsible for filtering your blood and removing wastes from your body.

March is Kidney Cancer Awareness Month and the second Thursday in March is World Kidney Day. After you’ve had all or part of your kidney resected in order to remove a tumor, there are certain things to keep in mind in order to preserve your remaining kidney function. Here are five things you should know:

  1. Certain medications may need to be adjusted or avoided. Medications should be dosed according to your level of remaining kidney function. This is called “renal dosing” and pertains to all medications filtered by the kidneys (which covers a diverse group ranging from certain medications for cholesterol, heart disease, blood pressure, diabetes, infections and pain). A medical oncologist who specializes in kidney cancer should take this into account when prescribing medications, including dosing for cancer treatments. Some over-the-counter drugs are also “nephro-toxic” or harmful to the kidneys. These include non-steroidal anti-inflammatory drugs (NSAIDs), a type of pain medication that includes ibuprofen (Advil®), aspirin and naproxen (Aleve®).
  2. Speak up before imaging tests. Certain imaging tests that might be necessary to see what’s going on in your body and determine whether your cancer has spread, require the injection of contrast dyes. It’s critical to tell the imaging technician that you only have one kidney before undergoing these tests or any procedures. You should also hydrate before and after the test, and you may need to stop taking certain medications beforehand, such as metformin for diabetes. It’s important to discuss your specific situation with your healthcare team before you undergo any procedures.
  3. Drink up! Drinking plenty of water and staying hydrated is important on an ongoing basis, not just when undergoing imaging tests. Being hydrated helps your kidneys filter the wastes and toxins out of your blood so that they can leave your body as urine. Aim for your urine to be clear or pale yellow. Staying hydrated also helps prevent kidney stones.
  4. Watch the sugar and hold the salt. Diabetes and high blood pressure can damage the kidneys, so it’s important to monitor your sugar and salt/sodium intake. People with only one kidney should consume less than 2300mg sodium each day. This is approximately one teaspoon of salt. Those with diabetes should regularly check blood sugar levels. Additionally, maintaining a healthy weight and incorporating physical activity can help prevent developing type II diabetes.
  5. Know your numbers. There are certain blood and urine tests that you’ll want to monitor for changes in your level of kidney function over time. These include your estimated glomerular filtration rate (eGFR) which indicates how well your kidneys are filtering the wastes from your blood, the albumin to creatinine (A:C) ratio which indicates the level of protein in your urine, as well as tests for blood and infection. Work with your primary care physician to make sure you’re receiving these tests on an annual basis and you should see a nephrologist (kidney function specialist) if your eGFR is less than 30 milliliters per minute (ml/min) or if you have large amounts of blood or protein in the urine.