A low anion gap refers to an excess of free radicals in the blood, explains Dr. Jeremy E. Kaslow. Causes of this condition include alkalosis, the overproduction of alkaloids and a low blood sodium level. Hypoalbuminaemia is also a key cause of a low anion gap, notes AnaesthesiaMCQ.
The anion gap is a measure of charged molecules, also referred to as ions, in the blood, explains Dr. Kaslow. The charge is either be positive or negative. Positively charged ions are known as cations, and their negatively charged counterparts are known as anions. The body's major anions are bicarbonate and chloride; its major cations are potassium and sodium. Minor anions include phosphates, albumin and sulfates, while minor cations include calcium and magnesium. Minor anions and cations are typically not measured; the anion gap is the result of a preponderance of unmeasured anions.
The optimal value of an anion gap ranges from 10 millimoles to 12 millimoles, notes Dr. Kaslow. For the body to function correctly, cations and anions must balance out. An excess of anions causes reduced energy production at the cell level. Elevated anion levels are typically the result of inadequate acid removal or excess acid production. Too much acid in the body leads to poor appetite, fatigue, low blood pressure and a rapid respiration rate. A low anion gap is associated with bromine ingestion, lithium poisoning, excess chloride and multiple myeloma.