High potassium, or hyperkalemia, is a common problem among people with kidney disease. If you have a chronic kidney disease (CKD), you’re up to three times more likely to experience high potassium levels in your blood than someone who doesn’t have kidney disease.

Signs of high potassium can be subtle, but you should never ignore them, because hyperkalemia can become life-threatening. It’s important to stay in tune with the signals your body gives you while living with a kidney disease and tell your doctor if you notice any changes.

How Do Kidney Diseases Cause High Potassium?

Potassium is an essential mineral that your body needs to work properly. It is also an electrolyte that helps carry signals in different tissues of the body. Your body gets potassium from food and uses it to support muscles, nerves, and the heart. Healthy kidneys remove extra potassium from the blood. When kidneys are damaged, they can’t remove potassium as well, so it can build up in the bloodstream.

Hyperkalemia is more common in later stages of kidney disease than in early stages. Certain factors can make high potassium even more likely in people with CKD.

When kidneys are damaged, they can’t remove potassium as well, so it can build up in the bloodstream.

Certain Medications

Some medications affect how potassium is eliminated by the kidneys, which raises your blood potassium levels. These include medications you might take for your kidney disease or associated high blood pressure, like angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). Other medicines, like water pills that keep potassium in the body or certain herbal supplements, can also cause potassium to increase in the blood.

Dialysis Complications or Other Diseases

If you’re on dialysis, the potassium in your dialysate (dialysis fluid that balances your electrolytes) may be too high and can contribute to high blood potassium levels. Your doctor can lower it if this is the case.

Diseases other than CKD, like heart disease and diabetes, can damage your kidneys further or affect the way your body uses potassium, leading to higher levels of potassium in the blood.

High-Potassium Foods and Salt Alternatives

Foods such as spinach, chard, bananas, pomegranate, avocados, beans, legumes, nuts, yogurt, certain seafood, and meat contain a lot of potassium, so if you eat them often, you’re more likely to experience hyperkalemia in CKD.

Most dietary salt is mainly made of sodium chloride. If you’re trying to cut down on salt in your diet, watch out for salt substitutes containing potassium chloride, as these can contribute to high potassium in CKD.

Hormone Imbalances

Imbalances of the hormone aldosterone may cause high potassium because aldosterone regulates sodium and potassium in your kidneys. Conditions with low aldosterone can increase your blood potassium. Insulin deficiency in diabetes can also lead to elevated potassium levels in the blood, as insulin normally helps drive the potassium into cells.

5 Symptoms of High Potassium

High potassium in CKD can be dangerous as it is often symptom-free and detected through blood work. A serum potassium test measures potassium levels and may be ordered if you’re at risk for hyperkalemia, even if you don’t notice symptoms.

The higher your blood potassium, the more likely you are to experience hyperkalemia symptoms. You’re also more likely to experience symptoms if your potassium levels increase rapidly. Watch out for these common signs of high potassium:

1. Muscle Weakness

You might experience muscle weakness with high potassium, which usually starts in your legs before moving upward to your core and arms. Muscle weakness is one of the most serious signs of hyperkalemia, signaling that potassium levels are very high or have spiked rapidly. For some people, this muscle weakness or paralysis can show up with increased fatigue or excessive tiredness.

Muscle weakness is one of the most serious signs of hyperkalemia.

Members of MyKidneyDiseaseTeam have described fatigue and weakness that may come from high potassium levels related to kidney disease. As one member described, “I am having a bad day because my back hurts and my legs keep giving in, going weak, not holding me up.”

2. Numbness and Tingling

You might also experience numbness or a loss of sensation in your limbs when dealing with high potassium. Similarly, some people describe a tingling sensation in their arms or legs. Numbness and tingling often start slowly when they’re related to hyperkalemia, and they may come and go.

These hyperkalemia symptoms come up in conversations on MyKidneyDiseaseTeam. “Tired, tingling in my left leg,” one member said.

3. Nausea

You might often feel nauseous because of high potassium, even to the point of vomiting. These symptoms can appear with acute hyperkalemia (high potassium that appears suddenly). In cases of chronic hyperkalemia (high potassium that develops slowly), mild nausea can come and go.

4. Abdominal Pain

A stomachache, possibly with diarrhea, is one of the milder signs of hyperkalemia. You might not assume your abdominal pain or cramps come from high potassium at first, but be sure to mention it to your doctor or nephrologist if you have kidney disease, just in case.

One member of MyKidneyDiseaseTeam described having this pain: “I always have pain in the lower stomach. I don’t know what to eat and am so tired of feeling like this.”

5. Heart Rhythm Changes

High levels of potassium in your bloodstream can damage your heart, which is a main reason why untreated hyperkalemia can be so dangerous to your health. Heart-related symptoms of high potassium should never be ignored, because this damage can lead to a heart attack, which is a life-threatening event.

Heart complications from hyperkalemia start with heart arrhythmias (abnormal, fast, or irregular heartbeats) or palpitations (a pounding or skipping heartbeat). You might initially assume a fluttering heart — sometimes accompanied by chest pain — comes from a more common (and harmless) cause, like anxiety or too much caffeine. Palpitations are also a common sign of low potassium (hypokalemia).

When To Seek Medical Attention

High potassium often doesn’t cause symptoms. Still, tell your doctor or nephrologist right away if you notice possible symptoms, even if they seem mild or vague. Even mild or chronic hyperkalemia can damage the heart, so early diagnosis and treatment are essential.

Your doctor can then provide a serum potassium test to diagnose or rule out high potassium. They might also suggest an electrocardiogram (EKG) to monitor your heart rhythm for changes that indicate high potassium.

Your doctor might order regular potassium tests for you if you’re at an increased risk for hyperkalemia to make sure your potassium levels stay within a safe range. They can give you suggestions for managing your potassium levels in kidney disease, including tips for a kidney-friendly diet.

When Hyperkalemia Is an Emergency

Hyperkalemia can be an emergency requiring immediate medical care. Go to the emergency room or call 911 if you notice any severe signs of hyperkalemia, especially if you have a chronic kidney disease or take medications that influence potassium, like ACE inhibitors or ARBs. The most severe signs of hyperkalemia include heart symptoms, as well as:

• Chest pain
• A weak pulse
• Irregular heartbeat
• Muscle weakness or paralysis
• Numbness
• Severe nausea, vomiting, or abdominal pain
• Shortness of breath

Some of these symptoms, like chest pain or a weak pulse, could be telling you a heart attack is already happening.

Join the Conversation

On MyKidneyDiseaseTeam, people share their experiences with kidney disease, get advice, and find support from others who understand.

Which signs of high potassium have you experienced? Let others know in the comments below.