Hyperkalemia and Hyponatremia Causes and Risk Factors

Causes of Hyperkalemia

The American College of Cardiology recommends considering chronic kidney disease as the most common cause of hyperkalemia, with incidence increasing dramatically as eGFR declines, occurring in up to 73% of patients with advanced CKD 1
The National Kidney Foundation states that acute kidney injury is often accompanied by acute pancreatitis or hepatic failure, and was present in all cases of hyperkalemia-induced cardiac arrest in one retrospective analysis 1
The European Society of Cardiology notes that medications, particularly RAAS inhibitors, potassium-sparing diuretics, NSAIDs, trimethoprim, and pentamidine, can cause hyperkalemia in up to 40% of heart failure patients and 5-10% with combination therapy 1
The American Heart Association recommends recognizing that metabolic acidosis causes potassium to shift out of cells in exchange for hydrogen ions, and insulin deficiency impairs cellular potassium uptake via Na/K-ATPase 1

The British Journal of Pharmacology reports that hyponatremia in patients with kidney disease or heart failure results primarily from impaired free water excretion due to elevated antidiuretic hormone (ADH) levels, combined with neurohormonal activation and medication effects 2
The European Society of Cardiology states that reduced cardiac output leads to decreased renal perfusion, causing activation of the renin-angiotensin-aldosterone (RAA) system and increased ADH secretion, which promotes water retention and dilutional hyponatremia 2
The American College of Cardiology notes that loop diuretics promote natriuresis by reducing sodium reabsorption via the NKCC transporter in the loop of Henle, resulting in sodium loss that can contribute to hyponatremia when combined with water retention 2
The National Institute of Diabetes and Digestive and Kidney Diseases recommends recognizing that impaired renal function reduces the kidney's ability to excrete free water, particularly when GFR is significantly reduced 2
The American Heart Association states that thiazide diuretics are particularly associated with hyponatremia due to their effects on the distal tubule and impaired diluting capacity 2
Nature Reviews Cardiology notes that increased sodium consumption during travel or eating out can paradoxically worsen fluid retention in heart failure patients, though this typically causes hypervolemic hyponatremia rather than true sodium depletion 3