Increased intake: potassium supplementation, red blood cell transfusionImpaired excretion: kidney disease, congestive heart failure, cirrhosis, medications (potassium-sparing diuretics, ACE inhibitors, ARBs, heparin), hypoaldosteronismTranscellular shifts: insulin deficiency, acidosis, medications (BBs, digoxin toxicity)Pseudo-hyperkalaemia: haemolysis, leucocytosis (>75 000 cells per mm3), erythrocytosis, thrombocytosis. The gene discussed is ACE; the disease is polycythemia.