disease are essentially the opposite of symptoms of Cushing’s disease, since they’re caused by a deficit in cortisol rather than an excess. Addison’s symptoms can include fatigue, weight loss, muscle wasting, mood swings and changes to the skin. Symptoms of adrenal fatigue can be similar. Symptoms of High Cortisol Levels According to research done by the Genetics Learning Science Center, the long-term danger of having high cortisol is that it activates the fight-or-flight response, which temporarily shuts down normal reproductive, digestive and immune functions. The body targets these systems for shutdown because it doesn’t need them for immediate survival. Sensory nerve cells pass the perception of a threat, or stress, from the environment to the hypothalamus in the brain.