###Human: Can high potassium level cause nauseous and numbness feeling? ###Assistant: Hello. Yes, serum potassium of 5.5 mEq is a bit high. The usual range of serum potassium is 3.5 to 5 mEq/L. Although 5.5 mEq/L is not that high to produce symptoms, but as your query suggested you are feeling the irregular heartbeat, I would suggest you get an ECG (EKG) done at the earliest. You might need medications to control the hyperkalemia (increased potassium). Regarding the history of cancers in your family, I cannot comment upon the hyperkalemia developing due to it or not.