This is a descriptive, retrospective study involving patients from private cardiology, nephrology, and dialysis clinics in Brazil who participated in the National Hyperkalaemia Diagnosis Campaign. The study used anonymised data from the Hi Technologies Ltda. database. The objective was to estimate and characterise the prevalence of hyperkalaemia (HK), as well as to analyse the demographic profile, clinical characteristics, risk factors and treatment patterns associated with total blood potassium levels.