Hyperkalemia (from English "hyper" meaning "high", "kalium" meaning "potassium") is elevated concentration of the electrolyte potassium K+.

• Ineffective elimination, including:
  • Renal insufficiency
  • Drugs, that interfere w/ urinary excretion, including:
    • ACEi's and ARB's
    • Potassium-sparing diuretics, e.g. amiloride and spironolactone
    • NSAID's, e.g. ibuprofen, naproxen, celecoxib
    • Calcineurin inhibitor immunosuppressants ciclosporin and tacrolimus
    • Antibiotic trimethoprim
    • Antiparasitic drug pentamidine
  • MIneralocorticoid deficiency or resistance, e.g.:
    • Addison's disease
    • Aldosterone deficiency
    • Some forms of congenital adrenal hyperplasia
    • Type 4 renal tubular acidosis (resistance of renal tubules to aldosterone)
  • Gordon's syndrome (pseudohypoaldosteronism type 2)
• Excessive release from cells, including:
  • Rhabdomyolysis, burns, or any cause of rapid tissue necrosis, including tumor lysis syndrome
  • Massive blood transfusion or massive hemolysis
  • Shifts/transport out of cells caused by:
    • Acidosis
    • Low insulin levels
    • Beta-blocker therapy
    • Digoxin overdose
    • Paralyzing agent succinylcholine
  • Box jellyfish venom
  • Acute digoxin toxicity, may cause hyperkalemia
• Excessive intake, w/ potassium salt-substitute, potassium-containing dietary supplements, or potassium chloride (KCl) infusion
• Pseudohyperkalemia, a rise in the amount of potassium that occurs due to excessive leakage of potassium from cells, during or after blood is drawn

• Non-specific Sx

• Blood test, usually performed for another reason

• Calcium, as calcium chloride, calcium gluconate, or [calcium] resonium, to increase the threshold potential, thus restoring normal gradient between the threshold potential and the resting membrane potential, which is elevated abnormally in hyperkalemia
• Removal of excess potassium is usually necessary, by:
  • Stimulating urine production
  • Through dialysis

• Potentially fatal arrhythmias (i.e. abnormal heart rhythms)

• Extreme hyperkalemia is a medical EMERGENCY

• Hypokalemia (antonym, LOW concentration of potassium K+ in blood)