Stress activates your sympathetic nervous system. This is your ‘fight or flight’ response, which triggers the release of hormones known to increase glucose levels.
This rush of fuel prepares your body with energy to overcome the stressor. This adaptive response is a survival mechanism to physical threats, and stress in your daily life can elicit that same response even though the perceived danger might come from emotional and environmental stressors. Stress can also be chronic, resulting in a maladaptive response and cascade of negative metabolic consequences.
References:
1. Nicolaides NC, Kyratzi E, Lamprokostopoulou A, Chrousos GP, Charmandari E. Stress, the stress system and the role of glucocorticoids. Neuroimmunomodulation. 2015;22(1-2):6-19. doi: 10.1159/000362736. Epub 2014 Sep 12. PMID: 25227402.