Causes

• haemolysis (e.g. poor venepuncture, blood dyscrasias) 

Note:

• Around 20% of samples found to have high potassium levels on laboratory testing are haemolysed ^c
• Patients with platelet counts > 500 are at increased risk of having a raised potassium (NNH = 29). Potassium levels increase by ~0.3 mmol/l. ^c