Extended anxiety puts the adrenal gland under enormous pressure to try and keep up with the production of cortisol. This eventually can lead to a group of symptoms that some medical practitioners call adrenal fatigue.
People with adrenal fatigue typically feel drained in the morning and don't feel fully awake until noon, with lulls in energy all day.
Other symptoms include inability to lose weight, difficulty remembering things, colds and lightheadedness.