Low total carbon dioxide is usually a sign of hyperventilation. 1. In some cases of abnormal emotional excitement, or when patients have seizures, convulsions, clonus, etc., they will exhale excessive carbon dioxide, and therefore low total carbon dioxide will be measured in the blood gas analysis. 2, In some metabolic diseases, such as hypothyroidism and adrenal cortical insufficiency, there are clinical signs and symptoms of low total carbon dioxide in the body due to dysfunction of carbon dioxide metabolism.