My wife is having multiple symptoms that are not always there. She was cleared for heart issues, lung issues, and blood work. But her symptoms persist. One is low grade pain in the jaw like when you chew too much gum. Another is a shaky feeling. Another symptom is anxiety which may be due to fear of the unknown about what is going on. She spent time in the hospital doing all sorts of tests with no problems found. Her doctor is guessing this may be a viral infection. Day to day the symptoms come and go. For sure she is weakened and suffers from a lack of energy.