Has your nephrologist recently talked to you about your potassium levels? If you live with a chronic kidney disease (CKD) like complement 3 glomerulopathy (C3 glomerulopathy, or C3G) or immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN), your doctors probably look at and monitor this number regularly.

If you have hyperkalemia (high potassium) or you’ve been told to look out for it, here’s what you need to know. Understanding the relationship between your kidneys and your potassium levels can help you understand your test results and decide what to do about them when your kidneys aren’t working as well.

Potassium and Your Kidneys

If you’re living with a chronic kidney disease, it means your kidneys are being damaged over time. These diseases tend to specifically damage your glomeruli, which are tiny blood vessels that allow your kidneys to work. They remove potentially harmful substances so you can get rid of them through your urine.

As your body takes in potassium from food and beverages, the glomeruli are designed to filter out the excess. If you have CKD, this filtering can weaken over time. When that happens, your kidneys may not remove enough potassium. This can cause potassium levels in your body to rise. In fact, chronic kidney disease is the most common cause of high potassium levels.

Triggers of High Potassium Levels

A number of factors can make your potassium levels rise. One of the most common is anything that triggers your chronic kidney disease. People with CKD often have ongoing inflammation. If your CKD flares or gets worse, that inflammation can increase. This makes it harder for the glomeruli to work properly, which can lead to higher potassium levels in your body.

Many different medications can also lead to high potassium levels. Some may be used to treat your chronic kidney disease, while you may take others for unrelated health conditions. These medications include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Certain blood pressure medications
• Certain immunosuppressant medications
• Some antibiotics
• Some diuretics or water pills (medications that help your body lose extra water) that cause potassium retention
• Certain herbal, vitamin, or mineral supplements
• Salt substitutes

Many different medications can lead to high potassium levels.

If you’re using any of these types of medications or supplements and you end up with high potassium levels, talk to your doctor about whether you need to switch to a different treatment.

Finally, since potassium leaves your body through your urine, not urinating enough can cause your potassium levels to go up. Some people urinate less due to chronic kidney disease, which could make it harder to get rid of potassium. Similarly, if you’re not drinking enough water and you’re dehydrated, your potassium levels may rise.

Symptoms of High Potassium

Many people with high potassium levels don’t know it because they don’t have any symptoms. When symptoms do happen, they may be mild, vague, or come and go. Because of this, people may not realize that something serious is happening.

Many people with high potassium levels don’t know it because they don’t have any symptoms.

Symptoms you might experience include:

• Tingling
• Numbness
• Nausea
• Weak muscles
• Stomach pain
• Diarrhea

If your potassium levels rise very fast or get very high, you may experience more symptoms. This is a serious medical condition, and you need to get medical care right away. It can become life-threatening if not treated quickly. You may experience:

• Nausea, with or without vomiting
• Heart palpitations (fast or pounding heartbeats)
• Shortness of breath
• Chest pain
• Significant numbness or muscle weakness

If you experience any of these symptoms, seek medical care immediately.

Diagnosing High Potassium

High potassium is generally easy to diagnose and track. Your nephrology team will take a sample of your blood to see how much potassium is in it. In some cases, they may also order a heart test called an electrocardiogram. This test measures your heart rhythm. Changes in this rhythm can be a sign of high potassium. Most times, though, a blood test is enough.

Normal blood potassium levels are usually between 3.5 and 5 millimoles per liter. Potassium is considered high when it’s over 5, and most symptoms show up when it’s over 6 millimoles per liter. You may also see symptoms if the level rises quickly. Some people won’t ever experience symptoms, which is why regular blood tests with your doctor are so important.

Managing High Potassium Levels

There are several ways you and your doctor can manage high potassium levels. You may use one approach or a combination of methods. The best plan depends on how high your potassium level is, how quickly it changes, and how well you tolerate medications.

Monitoring

Tracking your potassium level over time is an important part of managing it. Monitoring alone won’t lower potassium, but it helps you and your healthcare team know when treatment is needed, whether treatments are working, and when changes may be necessary. Potassium levels can also give your doctor clues about whether your kidney damage is getting worse.

Tracking your potassium and overall kidney health can also help identify medications that may be raising your potassium levels. If this happens, your doctor can adjust your treatment to lower potassium while still meeting your other health needs.

Medications

Sometimes, healthcare professionals prescribe medications to help lower potassium levels. One option is potassium binders. These medications attach to potassium in your digestive tract and make it easier to remove it in your stool, instead of letting it enter your bloodstream.

Doctors may also prescribe diuretics. These medications make you urinate more, helping you get rid of the potassium in your kidneys. However, if your kidney function is low, like in stage 4 kidney disease, diuretics may not work as well, because your kidneys may not be able to produce more urine.

If your potassium level is very high, doctors may give you several medications intravenously. These can include calcium gluconate to protect your heart. They may also give insulin — which helps move potassium into your blood cells — and albuterol. Albuterol is usually used for asthma, but it can also help lower potassium levels.

Dialysis

If your kidneys have lost much of their function, your potassium levels won’t go down, or you have kidney failure, your doctor may recommend dialysis. Dialysis is a treatment that helps your body remove potassium and other wastes from your blood. Your nephrologist will explain how dialysis works to you in detail and will let you know what to expect so you don’t feel overwhelmed or anxious about the process.

Dietary Changes

Lowering the amount of potassium you consume can also help manage high potassium levels. Your doctor or a registered dietitian can help you figure out what foods to limit or avoid.

It’s important not to cut out potassium completely. Your body needs some potassium to function. Your doctor can tell you how much you need, and a dietitian can help you create a meal plan that keeps your levels in a healthy range.

Talk to a Doctor About Your Potassium Level

If you have high potassium or are at risk for it, talk to your doctor. They can help you with testing, treatment, and ongoing monitoring. This support can help you better manage kidney disease and understand what’s happening in your body.

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How have you handled high potassium levels due to a rare kidney disease? Let others know in the comments below.