Glucose provides the necessary fuel to cover the physiological functions of the organism. In the brain, glucose represents the main energy supply through the generation of adenosine triphosphate, with oxygen and glucose being the main components involved. The imbalance in glucose levels in the central nervous system produces substantial changes in metabolism. Hypoglycemia, or decreased blood glucose levels below 50 mg/dl, is accompanied by symptoms such as decreased performance of cognitive tasks such as verbal fluency, reaction time, arithmetic ability, verbal memory and visual, in addition to excitotoxicity, oxidative stress, neuroinflammation and apoptosis. Hyperglycemia participates in some cardiovascular diseases, neuropathy, nephropathy, retinopathy. Changes in glucose metabolism must be regulated and considered in order to obtain the best treatment for different pathologies, such as infections, non-infections, traumatic, primary or acquired.