The abbreviation mEq stands for which unit?

• A. Milligram
• B. Milliequivalent
• C. Microgram
• D. Continuous Positive Airway Pressure

Answer: (B)

mEq stands for milliequivalent, a unit that expresses the amount of a substance based on its electrical charge. This matters because electrolytes are ions with different charges, so dosing by mass alone can be misleading. Milliequivalents reflect how much charge the ions can contribute or neutralize in solution. For monovalent ions like sodium or potassium, 1 mEq roughly equals 1 mmol of ion (same charge, same mole). For divalent ions like calcium or magnesium, 1 mEq equals 0.5 mmol because each ion carries two charges. That’s why concentrations are often given as mEq/L to convey the effective amount of charge available. The other options are units of mass or refer to a device, not a unit of charge, so they don’t describe this concept.