What are some symptoms of a low anion gap?

If a blood test shows that a patient has a low anion gap, he may experience symptoms such as fatigue, nausea and low blood pressure, states the University of Rochester Medical Center. Rapid heart rate and shortness of breath are also common symptoms.

The anion gap blood test measures the acid-base balance within a patient's blood, states the University of Rochester Medical Center. The anion gap value shows the doctor the concentration of charged particles in the patient's blood. If a patient's anion gap is low, then he may have a rare condition known as multiple myeloma, states MedicineNet. More commonly, if a patient's anion gap value is too high, he may be suffering from metabolic acidosis.