A person under lots of stress can be more prone to these than those that aren't.
Candida, a type of yeast infection
, can cause some of these issues as well. it is difficult to diagnose, most do it via elimination of yeast containing foods, drugs, vitamins, etc. Candida can cause a weakened immune system and this in turn can cause the issues. Are you exposed to a lot of chemicals, or molds, if so, try to avoid them and yeast foods and see how you feel.