That's really what's happening when you can't maintain your energy levels, which may eventually lead to a major short-circuiting of your energy system. These kinds of massive energy drops are ultimately an energy crisis in your body, much like having a blown fuse in your body that needs to be reset. The most common causes of lack of energy are detected the old-fashioned way and you can make the diagnosis with a little insight. Culprits include not enough sleep, too much food, too much saturated fat and sugary foods, too much stress, not enough fun and passion in life, or an infection or other chronic disease. Even seemingly mundane things such as sinusitis, gingivitis, and vaginitis can stimulate this.
Once your resilience is gone, you're more prone to being attacked by bacteria, viruses, or fungi. Even the ensuing insomnia and stress that come as a result of those attacks can wear down your adrenal glands, creating a vicious cycle where smaller and smaller problems cause progressively larger challenges until you experience a complete health shutdown.