A low anion gap means blood has abnormal proteins with a positive charge, explains MedicineNet. The anion gap is the difference between the positively charged sodium and potassium ions and negatively charged chlorine and bicarbonate ions.
A low anion gap in the blood might be a sign of multiple myeloma, according to MedicineNet. It is also a sign of hypoalbuminemia, notes the University of Rochester Medical Center. Multiple myeloma is a blood cancer that arises from the uncontrolled growth of plasma cells, states Mayo Clinic. These cells accumulate in the patient's bone marrow and overwhelm the other blood cells created there. They also produce abnormal proteins that damage the kidneys. This is what is detected in the anion gap test. Fortunately, multiple myeloma can be asymptomatic and does not always need to be treated.
Hypoalbuminemia is a condition where the protein albumin in the blood is less than 3.4 to 3.5 grams per deciliter, or g/dL, according to Nutrition Care Systems. It is most often seen in elderly patients who are hospitalized and patients who are in the end stages of diseases such as cancer. A low level of albumin is a good predictor of mortality and morbidity. The causes of low albumin are mostly acute and chronic inflammatory diseases, cirrhosis of the liver, kidney disease, malnutrition and heart failure.