I am 61 yrs old. I have had these symptoms twice before, saw several doctors and none seem to be able to figure out what s wrong: symptoms are nausea, tired, weak, some times shortness of breath, and light headedness once in a while, diahrea, dry scummy mouth for last 2 weeks. This time have had these symptoms for almost 4 weeks. Have a little bit of sinus issue right now also. 1st time I had all these symptoms they lasted several months. I have Rhuematoid Arthritis and I also have Celiacs Disease. After having these symptoms for several month the 1st time they did endoscopy, stress test, ekg or eeg (not sure which one) and also had full pulminary breathing test. They didn t find anything wrong from those tests.