Since my last post about stress, I’ve gotten a lot of questions about what all stress does to the brain. Stress has a lot of big, widespread effects on both the nervous system and the body.
Stress increases production of the hormones epinephrine (aka adrenaline) and norepinephrine (aka noradrenaline) and enhances activity of the sympathetic nervous system. The sympathetic nervous system is responsible for “fight or flight” responses systemically and increases heart rate, dilates the lungs (so you can get more oxygen), increases blood pressure, etc. All of the things your body would need to do to be able to run away quickly or put up a good fight. It also decreases activity in parts of the body that aren’t as necessary to conserve energy- for instance, it decreases metabolism and the immune system.
When all of these things happen short term, it’s actually good- you can put all your energy towards solving the problem that is making you stressed and respond to emergency situations better. Long-term stress means you will put on more weight (due to decreased metabolism), be more prone to illness (due to suppressed immune system), have high blood pressure, etc. This isn’t to say you want to prevent stress- it’s all about managing stress so that your body can use it appropriately.