The definition and approach of hyperlactatemia classically has been related to tissue hypoperfusion, hepatic insufficiency, and anaerobic metabolism. Nonetheless, there are few aetiologies known which could produce it. Muscle fatigue in patients with chronic obstructive pulmonary disease (COPD) or asthma, as well as the use of inhaled B2 agonist, is associated with hepatic noradrenaline release, activation of glycolysis (converting glucose to pyruvate or lactate), and consequently, an increase in lactate.