Definition
A milliequivalent (mEq) is a unit of measurement used to express the concentration of electrolytes in a solution. It represents one-thousandth of an equivalent. This unit is commonly used in medicine to measure the amount of electrolytes like sodium, potassium, and chloride in blood and other bodily fluids. It helps doctors assess electrolyte balance, which is crucial for proper bodily function. Think of it as a tiny unit for measuring the 'active' part of a substance.