Too Much Potassium (Hyperkalemia): Causes

Pathogenesis (development of disease)

More than 98% of the potassium in the body is in the intracellular space (IZR = fluid located inside the body’s cells)

The distribution of potassium between extracellular volume (EZR = intravascular space (located inside the vessels) + extravascular space (located outside the vessels)) and IZR is influenced by the following factors:

The balance of body potassium occurs primarily through the kidney. There, potassium is filtered glomerularly. About 90% of the filtered potassium ions are reabsorbed in the proximal tubule (main piece of the renal tubules) and in Henle’s loop (straight sections of the renal tubules and transition piece). In the distal tubule (middle section of the renal tubules) and in the collecting tubule of the kidney, the decisive regulation of potassium excretion finally occurs. For details, see Potassium/Definition, Synthesis, Absorption, Transport and Distribution. The following factors favor the development of hyperkalemia:

  • Increased potassium intake (but only in patients with impaired renal function) (e.g., because of blood transfusion, potassium-containing drugs (penicillin), malinfusion).
  • Shift from intracellular potassium to extracellular, i.e., increased release of potassium from the cells into the extracellular space (space that is outside the cells and contains the extracellular fluid) (e.g., due tometabolic acidosis, hyperosmolarity, hyperglycemia/hyperglycemia)
  • Decreased renal (“kidney-related”) elimination (renal insufficiency).

Aldosterone promotes renal excretion of potassium ions and, at the same time, sodium and water reabsorption. Since aldosterone itself is under the control of the renin-angiotensin system (RAS), any inhibition of this system can lead to an increase in serum potassium concentration. Aldosterone is produced in the adrenal cortex, which is why diseases of the adrenal gland (e.g. Addison’s disease = primary adrenocortical insufficiency) also cause hyperkalemia. Aldosterone antagonists can thus lead to hyperkalemia.

Etiology (causes)

Behavioral causes

  • Diet
    • Fasting
    • Increased intake of potassium; hyperkalemia due to increased dietary potassium intake occurs only in patients with impaired renal function (most common cause of hyperkalemia)

Disease-related causes

Endocrine, nutritional and metabolic diseases (E00-E90).

  • BRASH syndrome
  • Diabetes mellitus (diabetes).
  • Gordon syndrome (synonym: pseudohypoaldosteronism type 2) – rare genetic form of hypertension (high blood pressure) characterized by hyperkalemia, mild hyperchloremic metabolic acidosis (metabolic acidosis), normal or elevated aldosterone, low renin with normal glomerular renal filtration rate (GFR).
  • Hyperglycemia (high blood sugar).
  • Hypoaldosteronism (primary and secondary; Addison’s disease) – reduction of aldosterone in the blood, which regulates salt-water balance.
  • Metabolic acidosis/metabolic acidosis (especially chloracidosis).
  • Adrenocortical insufficiency (NNR insufficiency; adrenocortical insufficiency), primary
  • Pseudohypoaldosteronism, renal, type 1 – very rare genetic metabolic disorder with autosomal dominant inheritance or even sporadic cases, occurring as a mild form of primary mineralocorticoid resistance confined to the kidney; it is associated with hypotension (low blood pressure), hyperkalemia, and metabolic acidosis (metabolic acidosis), among other symptoms; age of manifestation: infant age, neonatal period.

Psyche – nervous system (F00-F99; G00-G99).

  • Alcohol abuse (alcohol abuse)

Genitourinary system (kidneys, urinary tract – reproductive organs) (N00-N99).

  • Renal insufficiency, chronic (process leading to a slowly progressive reduction in renal function) (33-88% of cases)
  • Acute renal failure (ANV)

Medication

Other causes

  • Blood transfusion
  • Misinfusion
  • Hemolysis/dissolution of red blood cells (burn, trauma, transfusion).
  • Potassium-containing infusion solutions
  • Rhabdomyolysis/tissue dissolution of striated muscle.
  • Tumors, radiotherapy