What are the causes of hyperkalemia (elevated potassium levels) and hyponatremia (low sodium levels)?

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Last updated: June 10, 2025View editorial policy

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From the Guidelines

Hyperkalemia and hyponatremia are life-threatening electrolyte disorders that require prompt identification and treatment, with hyperkalemia resulting from decreased kidney excretion of potassium, cellular shifts, or excessive intake, and hyponatremia resulting from excess water retention or true sodium depletion. The causes of hyperkalemia include:

  • Decreased kidney excretion of potassium, as seen in acute or chronic kidney disease, adrenal insufficiency, and with medications like ACE inhibitors, ARBs, potassium-sparing diuretics (spironolactone, eplerenone), and NSAIDs 1
  • Cellular shifts of potassium into the bloodstream, such as acidosis, tissue breakdown, and insulin deficiency
  • Excessive potassium intake from supplements or salt substitutes
  • Pseudohyperkalemia from improper blood collection

On the other hand, hyponatremia can result from:

  • Excess water retention relative to sodium, as seen in heart failure, cirrhosis, and kidney disease
  • True sodium depletion through gastrointestinal losses (vomiting, diarrhea), excessive sweating, or diuretic use (especially thiazides)
  • SIADH (Syndrome of Inappropriate ADH secretion), which increases water reabsorption in the kidneys
  • Adrenal insufficiency, hypothyroidism, and medications like SSRIs, carbamazepine, and oxcarbazepine

According to the most recent study 1, the risk of mortality, cardiovascular morbidity, progression of CKD, and hospitalization is increased in patients with hyperkalemia, especially those with CKD, HF, and diabetes. Therefore, it is crucial to promptly identify and treat these conditions to prevent serious complications, including cardiac arrhythmias and neurological symptoms.

The management of hyperkalemia and hyponatremia involves addressing the underlying cause, and may include the use of medications such as potassium binders, loop diuretics, and vaptans, as well as lifestyle modifications, such as dietary changes and fluid restriction 1.

In summary, prompt identification and treatment of hyperkalemia and hyponatremia are crucial to prevent serious complications, and the management of these conditions should be tailored to the individual patient's needs and underlying cause.

From the FDA Drug Label

The risk for hyponatremia is increased in pediatric patients, elderly patients, postoperative patients, those with psychogenic polydipsia, and in patients treated with medications that increase the risk of hyponatremia (such as diuretics, certain antiepileptic and psychotropic medications). Patients at increased risk of developing hyperkalemia include those:

  • With conditions predisposing to hyperkalemia and/or associated with increased sensitivity to potassium, such as patients with severe renal impairment, acute dehydration, or extensive tissue injury or burns, certain cardiac disorders such as congestive heart failure
  • Treated concurrently or recently with agents or products that cause or increase the risk of hyperkalemia

The causes of hyperkalemia (elevated potassium levels) include:

  • Severe renal impairment
  • Acute dehydration
  • Extensive tissue injury or burns
  • Certain cardiac disorders such as congestive heart failure
  • Treatment with agents or products that cause or increase the risk of hyperkalemia The causes of hyponatremia (low sodium levels) include:
  • Pediatric patients
  • Elderly patients
  • Postoperative patients
  • Psychogenic polydipsia
  • Treatment with medications that increase the risk of hyponatremia, such as diuretics, certain antiepileptic and psychotropic medications 2

From the Research

Causes of Hyperkalemia

  • Hyperkalemia is caused by impaired renal excretion, transcellular shifts, or increased potassium intake 3, 4, 5
  • Kidney disease, hyperglycemia, and medication use are common causes of hyperkalemia 3
  • Medications such as inhibitors of the renin-angiotensin-aldosterone system, potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs, succinylcholine, and digitalis are associated with hyperkalemia 6
  • Underlying predisposing conditions, such as moderate or severe kidney disease, heart failure, diabetes mellitus, or significant tissue trauma, can also lead to hyperkalemia 6

Causes of Hyponatremia

  • There is no direct evidence in the provided studies to support the causes of hyponatremia, as the studies primarily focus on hyperkalemia and potassium disorders 3, 4, 7, 5, 6

Common Factors

  • Transcellular shifts can contribute to both hyperkalemia and hypokalemia, and patients are at increased risk of rebound potassium disturbances 3, 4
  • Electrocardiography changes can be an indication of both hyperkalemia and hypokalemia, and can be used to guide treatment 3, 4, 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Potassium Disorders: Hypokalemia and Hyperkalemia.

American family physician, 2015

Research

Potassium Disorders: Hypokalemia and Hyperkalemia.

American family physician, 2023

Research

Hyperkalemia treatment standard.

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2024

Research

Acute hyperkalemia in the emergency department: a summary from a Kidney Disease: Improving Global Outcomes conference.

European journal of emergency medicine : official journal of the European Society for Emergency Medicine, 2020

Research

Hyperkalemia: recognition and management of a critical electrolyte disturbance.

Journal of infusion nursing : the official publication of the Infusion Nurses Society, 2014

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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