What is the number one cause of high potassium?

October 1, 2025 •

3 min read

The most common cause of high potassium, or hyperkalemia, is chronic kidney disease (CKD). While most people with healthy kidneys can regulate their potassium levels effectively, those with impaired kidney function often struggle to filter excess potassium from their blood, leading to a dangerous buildup.

Quick Summary

The most prevalent cause of hyperkalemia is kidney disease, which disrupts the body's ability to excrete excess potassium. Other contributing factors include certain medications, other medical conditions like diabetes, and severe injuries. Treatment involves addressing the underlying cause and managing potassium levels through diet and medication.

Key Points

Kidney Disease is the Top Cause: Chronic and acute kidney disease are the most common reasons for high potassium (hyperkalemia) because impaired kidneys cannot effectively filter excess potassium from the blood.
Medications Can Contribute: Certain drugs, including ACE inhibitors, ARBs, potassium-sparing diuretics, and long-term NSAIDs, can raise potassium levels, especially in individuals with kidney problems.
Diet Is a Factor, Especially with Kidney Issues: While a high-potassium diet alone is rarely the sole cause in healthy people, it becomes a significant contributor for those with kidney disease.
Symptoms Are Often Subtle or Absent: Many people with mild hyperkalemia experience no symptoms, making routine blood testing for at-risk individuals crucial for early detection.
Treatment Focuses on Managing the Underlying Issue: Addressing the root cause, adjusting medications, and using potassium binders or dietary changes are key strategies for managing high potassium.
Hyperkalemia Can Be Life-Threatening: In severe cases, very high potassium can cause dangerous heart arrhythmias and cardiac arrest, requiring immediate medical attention.

What is high potassium (hyperkalemia)?

Potassium is an essential mineral and electrolyte vital for nerve and muscle function, as well as maintaining a regular heartbeat. Healthy kidneys regulate potassium levels by filtering excess amounts into urine. Hyperkalemia occurs when blood potassium levels become too high. While mild hyperkalemia may not present symptoms, severe cases can result in serious and potentially life-threatening heart issues.

The number one cause: Kidney disease

The leading cause of high potassium is kidney disease, encompassing both acute kidney injury and chronic kidney disease (CKD). This is due to the kidneys' primary role in removing excess potassium from the body. As kidney function declines, their ability to excrete potassium is reduced, leading to its accumulation in the bloodstream. This is particularly common in advanced CKD, with over 50% of individuals in these stages developing elevated potassium.

Why kidney function is so crucial

Healthy kidneys balance potassium intake from food with its excretion. When kidney function is compromised, this balance is disrupted, and excess potassium re-enters the bloodstream instead of being expelled through urine.

Other major contributors to high potassium

Beyond kidney disease, several other factors can contribute to hyperkalemia, often in combination with kidney issues.

Medications

Various medications can elevate potassium levels, particularly in those with pre-existing kidney problems. These include ACE inhibitors and ARBs which can interfere with potassium excretion, potassium-sparing diuretics that conserve potassium, NSAIDs which can damage kidneys with long-term use, and potassium supplements or salt substitutes that increase intake.

Other medical conditions

Other health issues affecting potassium regulation include poorly controlled diabetes (like diabetic ketoacidosis) causing potassium shifts out of cells, adrenal disorders (such as Addison's disease) impairing potassium excretion, and severe trauma or injuries leading to the release of cellular potassium into the blood.

High-potassium diet

A diet high in potassium is usually not a problem for healthy individuals, but it becomes a significant factor for those with kidney disease. Excessive intake of potassium-rich foods can overwhelm the reduced filtering capacity of compromised kidneys.

Comparing the causes of high potassium


Cause	Mechanism	Primary Risk Group	Severity of Risk
Kidney Disease (CKD)	Impaired kidney function reduces the excretion of excess potassium, causing it to build up in the bloodstream.	Individuals with chronic or acute kidney issues.	High: The most common and significant cause, with risk increasing as kidney function declines.
Certain Medications	Some drugs, like ACE inhibitors, interfere with the body's potassium regulation and excretion.	Those with kidney disease, heart failure, or those taking specific blood pressure drugs.	Moderate: Can significantly contribute to hyperkalemia, especially in at-risk individuals.
Diabetes	Conditions like diabetic ketoacidosis cause intracellular potassium to shift into the bloodstream.	Individuals with uncontrolled or poorly managed diabetes.	Moderate: Can lead to acute, severe spikes in potassium levels.
High-Potassium Diet	Excessive intake of potassium from foods, supplements, or salt substitutes.	Primarily a risk factor for individuals with underlying kidney dysfunction.	Low (for healthy individuals): Healthy kidneys can compensate. High (for CKD patients): Can be a major factor.
Trauma/Burns	Cellular damage releases large amounts of potassium into the bloodstream.	Individuals experiencing severe injuries or trauma.	High (Acute): Can cause a rapid, life-threatening spike in potassium.

Symptoms and management

Hyperkalemia symptoms vary from mild (nausea, muscle weakness) to severe (heart palpitations, irregular heartbeat). Often, there are no symptoms in mild cases, emphasizing the importance of routine blood tests for detection.

Management strategies depend on severity and cause and may include dietary changes to limit high-potassium foods (especially with kidney issues), adjusting contributing medications, using potassium binders to remove excess potassium via the bowels, or emergency treatments for severe cases (IV calcium and other medications). Addressing the underlying condition, such as kidney disease, is crucial for long-term management.

Conclusion

While various factors contribute to high potassium levels, chronic kidney disease is the most significant cause due to the kidneys' essential role in potassium regulation. Individuals with CKD or those on certain medications require proactive management, including dietary changes and regular monitoring, to prevent serious complications. Understanding the primary cause highlights the importance of kidney care and collaborating with healthcare professionals to manage this potentially dangerous condition.

For more information on kidney-related health topics, visit the National Kidney Foundation's official website.

Frequently Asked Questions

The most common cause of high potassium, known as hyperkalemia, is chronic kidney disease (CKD). When kidneys are not working properly, they cannot remove excess potassium from the blood, causing it to build up.

Early or mild symptoms of high potassium can be subtle or nonexistent. If they do occur, they may include muscle weakness, fatigue, and nausea. Because symptoms are often non-specific, hyperkalemia is frequently discovered during routine blood work.

Several types of medication can cause or contribute to high potassium levels, including ACE inhibitors, angiotensin receptor blockers (ARBs), potassium-sparing diuretics, and long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs).

For most healthy people, consuming a diet high in potassium does not cause hyperkalemia, as the kidneys are able to process and excr ete the excess. However, it can be a significant contributing factor for individuals with underlying kidney disease.

Emergency symptoms of severely high potassium can affect the heart and may include chest pain, heart palpitations or an irregular heartbeat, and severe muscle weakness. These signs require immediate medical attention.

Treatment for high potassium depends on the severity and cause. Mild cases may be managed with dietary changes and medication adjustments. Severe cases may require emergency medical treatment, including intravenous medications to stabilize heart function and lower potassium levels quickly.

Many fruits and vegetables are high in potassium. For individuals at risk of hyperkalemia, foods to monitor include bananas, potatoes, sweet potatoes, spinach, dried fruits, beans, and certain juices.