Işık, SerhatBerker, DilekAydın, YusufÖzuğuz, UfukTütüncü, YaseminŞimşek, YasinGüler, Serdar2020-04-302020-04-3020101841-0987https://doi.org/10.4183/aeb.2010.251https://hdl.handle.net/20.500.12684/4528WOS: 000287017600011Objective. Hyperkalemia is one of the most common acute life-threatening metabolic emergencies. Alterations in scrum potassium (K(+)) levels can have dramatic effects on cardiac cell conduction and may lead to electrocardiographic (ECG) changes. But in some patients ECG changes do not accompany serum K(+) abnormalities. Severe hyperkalemia secondary to Addison Disease (AD) is rare. Case. A 40-year-old woman with AD was admitted to emergency service with generalized pain. The patient's serum K(+) level was found to be at the highest level that can be detected in our laboratory (>10.0 mmol/L, normal 3.5-4.5 mmol/L) and repeated serum K(+) confirmed the previous result. Results of repeated ECGs have revealed a normal sinus rhythm. Our case is particularly interesting because it demonstrates an Addison patient that has an extremely high level of K(+) (>10 mmol/L) without any accompanying ECG changes. Conclusion. Our case confirms that diagnostic ECG changes do not always accompany severe hyperkalemia. Therefore, clinicians should be careful that ECG may look normal in the presence of severe hyperkalemia.en10.4183/aeb.2010.251info:eu-repo/semantics/closedAccessHyperkalemiaAddison Diseasechronic renal failureelectrocardiographyArticle62251255WOS:000287017600011N/AQ4