en Nephrology Nephrology case report case report <span style="font-family:times new roman;"><span style="color:#0000FF;"><strong><em>Background:</em></strong></span> Generally, it is very rare for clinically significant hypermagnesemia to develop in an individual with normal renal functions as the renal handling of serum magnesium is a very potent process and it has the capacity, under conditions of hypermagnesemia, to completely block Mg (magnesium) reabsorption from the thick ascending limb of Henle. Therefore, hypermagnesemia usually arises in the setting of renal failure.<br> <span style="color:#0000FF;"><strong><em>Case presentation:</em></strong></span> We present a very rare case of a 40-year-old African American obese female with prior normal renal functions, who presented post-cardiac arrest following accidental overdose of Epsom salt. The patient was initially given supportive therapy and was later considered for the dialysis despite normal renal functions, as serum Mg levels kept on creeping up and clinical status kept on deteriorating continuously.<br> <span style="color:#0000FF;"><strong><em>Conclusions:</em></strong> </span>Seemingly harmless magnesium containing (over-the-counter) (OTC) can potentially be lethal, and such consequences must always be taken into account when using such medications for a prolonged period of time.</span><br> &nbsp; Epsom salt, Magnesium, Hypermagnesemia, Normal Renal Functions 413 415 http://caspjim.com/browse.php?a_code=A-10-989-1&slc_lang=en&sid=1 Muhammad Shoaib Khan MShoaibKhanAimc@gmail.com 100319475328460014100 100319475328460014100 Yes Department of Cardiac MRI, Division of Cardiovascular Medicine, Allegheny General Hospital, Pittsburgh, USA Sohaib Zahid sohaib.zahid@ahn.org 100319475328460014101 100319475328460014101 No Department of Internal Medicine, Allegheny General Hospital, Pittsburgh, USA Muhammad Ishaq ishaq.muhammad@marshfieldclinic.org 100319475328460014102 100319475328460014102 No Department of Internal Medicine, Marshfield Clinic, Marshfield, USA