The most common cause of hypokalaemia is potassium depletion. In critically ill patients the most common cause is abnormal losses which occur in stool and urine (from metabolic alkalosis and chloride depletion).

Other causes of hypokalaemia are:

  • Increased potassium loss
  • Transcellular shift
  • Decreased intake
  • Magnesium depletion

The following pages outline these causes in more detail.

Other causes of hypokalaemia include:

Transcellular shift

  • Glucose insulin therapy
  • Theophylline, caffeine
  • Hyperthyroidism
  • β2 adrenergic stimulation, e.g. salbutamol nebulisers
  • Alkalosis
  • Hypokalemic periodic paralysis

Decreased intake

  • Iatrogenic, e.g. inadequate intravenous supplementation
  • Poor dietary intake

Magnesium depletion

  • Poor dietary intake
  • Increased magnesium loss