When you’re living with chronic kidney disease, your nephrology team may spend a lot of time talking about potassium. That’s because kidney disease can cause high potassium in your blood, a condition called hyperkalemia.

Other factors can lead to low potassium levels, known as hypokalemia. Your nerves, your muscles, and especially your heart need the right amount of potassium to function well. It’s important to know about what can cause your potassium levels to rise or fall when you have kidney disease.

Kidney Disease and Potassium Levels

Both kidney disease and its treatments can affect how your body handles potassium. This can make it harder to keep potassium levels balanced, sometimes leading to too much or too little potassium.

When kidney function is healthy, the kidneys remove excess potassium intake from your blood through urine. You get potassium from what you eat and drink, and your kidneys filter out what you don’t need. However, if your kidneys aren’t filtering properly, too much potassium can build up in your blood and affect the way your body functions.

Even with kidney disease, you can sometimes have low potassium. This can happen if you don’t consume enough potassium or if you lose it through diarrhea before your body has a chance to absorb it. However, if diarrhea causes dehydration, potassium levels can rise instead. Dialysis can also lead to low potassium, especially right after a treatment.

Medication Effects

Medications can also affect potassium levels. If your nephrologist is trying to lower high potassium levels, you might take diuretics (water pills) to help your body make more urine and remove extra potassium. However, some diuretics can reduce potassium levels too much.

Your doctor might also prescribe potassium binders, which attach to the mineral in your digestive system so you can pass it in your stool. These can help lower your levels, but it’s important to make sure they don’t drop too low.

Both kidney disease and its treatments can affect how your body handles potassium.

Low potassium can be life-threatening when not treated right away. Get medical attention quickly if you experience symptoms such as:

• Significant fatigue or weakness
• Sudden confusion, hallucinations, or depression
• Severe muscle pain or cramps
• Irregular heartbeats or heart palpitations

Some medications used to treat kidney disease or its complications may raise potassium levels as a side effect. These drugs may help protect your kidneys or help manage related symptoms, like hypertension (high blood pressure), and include:

• Beta-blockers
• Angiotensin-converting enzyme (ACE) inhibitors
• Angiotensin-receptor blockers (ARBs)
• Some calcium channel blockers
• Aldosterone antagonists
• Certain diuretics that retain potassium

Hyperkalemia can also be dangerous if not treated. Watch out for symptoms such as:

• Sudden weakness or heavy feeling in the muscles
• Tingling or numbness in arms or legs
• Chest pain
• Fast or irregular heartbeats or palpitations
• Abdominal pain
• Nausea

Dehydration and Potassium

Dehydration can affect potassium levels, especially when you’re living with chronic kidney disease. Getting enough fluid helps your kidneys get the blood flow and nutrients they need. Staying well hydrated also helps them make enough urine to remove waste, including extra potassium.

If your kidneys already have trouble filtering potassium, poor hydration can make the situation worse. Your kidneys may struggle even more and might not be able to self-correct to keep your fluid and mineral levels in balance. Common causes of dehydration include:

• Heavy sweating
• Vomiting
• Diarrhea
• Fever
• Lack of fluids

Any of these can throw off your potassium balance and cause levels to go up. If potassium gets too high, you may begin to experience muscle weakness or even develop heart problems.

If you get an illness like the flu and have several of these symptoms at the same time, your potassium levels can rise quickly. You might feel your heart pounding, have chest pain, feel short of breath, or experience additional nausea and vomiting. If this happens, you need urgent medical care. A spike in potassium can be life-threatening and may even cause a heart attack.

Illness, Stress, and Potassium

Even when it’s not the flu, other illnesses and stress can affect your potassium levels. The effects can vary based on the type of illness and how your body responds.

An illness that causes symptoms such as vomiting or diarrhea may raise your potassium levels for the same reasons explained in the previous section. Some medical conditions, such as diabetes and heart disease, are linked to high potassium levels. If you have any of these alongside chronic kidney disease, talk with your healthcare provider about how they may affect your potassium.

Both physical stress (such as from illness) and emotional stress can trigger responses that change how your body handles potassium. During stress, your body produces more of certain hormones, including cortisol, epinephrine (adrenaline), and aldosterone, which can change the way your body uses and stores potassium.

If you get an illness like the flu and have several of these symptoms at the same time, your potassium levels can rise quickly.

Aldosterone, for example, tells cells when to absorb or release potassium. High aldosterone levels can cause your kidneys to release too much potassium in your urine, leading to hypokalemia. High epinephrine and cortisol levels can also cause potassium to drop. If this happens too fast and you develop symptoms, you need medical attention right away.

Talk With Your Nephrologist

If you are concerned about your potassium levels or want to understand how chronic kidney disease affects them, talk with your nephrologist. They can help you track changes over time and use this information to understand your kidney function. Your potassium levels can also show your doctor how well your medications are working and if your treatment plan should be adjusted.

If you ever need urgent medical care because of a problem with potassium, be sure to follow up with your kidney doctor. They can help you figure out what happened and come up with ideas to prevent the issue in the future.

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What factors have changed your potassium levels? Let others know in the comments below.