I have been having muscle weakness and fatigue for over 3 weeks following a minor upper respitory infection. Lung X-ray showed no pneumonia. The fatigue was very bad and I get tired after minor activity such as vaccuming a room. The muscle aches started in the middle back and then spread to thigh muscles then after a few days my shoulders and biceps were so tired I couldn’t barely lift anything, then it moved on to my Neck muscle which were stiff and sore, then forearms, hamstrings, calves.