Do you ever ask yourself “what is stress?” You may cringe at the thought of being a worrywart. It doesn’t sound very attractive. Truthfully, it can get pretty ugly. Overtime, nagging stress ages our bodies from the inside out.Even if you consider yourself a Zen master, we all have days when a deadline or dinner party can throw us for a loop. Luckily, these occasional stresses aren’t the kind that will give you wrinkles and grays. Actually, when our nervous system reacts to challenges, it spurs us to rise to the occasion. So, what is stress exactly?QUIZ: Are You Feeling Stressed?The Biology of StressStress can definitely pump us up, but let’s get into how it can bring our bodies down. We have all felt ourselves get sick from too much stress—trouble sleeping, eating or even thinking straight with that nagging headache. If left unchecked, this can alter your emotions, hormones and immune system. It even increases your risk of heart disease.We know stress messes with the chemicals in our body, but how exactly? When you feel stress, it sparks a major communication loop—activating your nervous system and releasing stress hormones.This “stress circuit” is called the hypothalamic-pituitary adrenal (HPA) axis. It’s a mouthful to say, and a crazy cycle to follow. Here goes…Firstly, when you perceive a big stressor, the hypothalamus in your brain releases CRH, which triggers your pituitary gland to release ACTH into your blood. This hormone tells your adrenal glands to release yet another hormone, cortisol. This is known as the stress hormone for good reason. It makes your adrenaline surge.Everyone has a good idea of what that does. It’s the age-old fight-or-flight instinct our ancestors used to flee from predators. You know the feeling—heart racing, blood pressure spiking. Sometimes, real life can feel like you’re surviving the jungle.Oh, and did we mention what stress can do to the outside of your body? When metabolism and cholesterol levels get out of whack, you crave much more sugar (hello, aging body).WATCH VIDEO: What is Stress? Learn the Science Behind ItDifferent Kinds of Stress: Chronic, Acute and Major StressorsGenerally, chronic stress persists when we worry about the things we cannot control. Insecurities about our bodies, relationships or physical health may leave us feeling overwhelmed and powerless.Chronic stress that accumulates over time (nagging unfinished tasks—NUTs) will drive you nuts! Chronic stress ups anxiety and brings in headaches, migraines and tremors. It also raises your blood pressure. Acute stress, on the other hand, can be a good thing. An ongoing low level of stress is actually quite healthy. It allows you to think more clearly, increase concentration and improve performance. If you can keep your chronic stressors acute, you can resist the wear-and-tear of this ugly stress.Even if some damage has been done,it’s possible to reverse aging and your disease risk! The first step to this seemingly easy task is allowing yourself to learn how this is possible.While our worries are very particular to what’s going on in our lives, there are some universal stress sources.