Anxiety and stress can cause all kinds of physical symptoms.....I've had plenty of them and still do
But most of them, if not all, are all associated to somatization.
"Somatization is the process whereby you develop physical symptoms in response to psychological issues, often with an accompanying preoccupation with, and overreporting of, bodily sensations. You're conscious of a multitude of physical symptoms -- many seemingly unrelated -- that seem to rule your life, but you're not conscious of the mental conflicts that are producing your symptoms. Obviously, many cases of health anxiety syndrome involve some element of somatization." -George Zgourides, Psy.D.
Basically, you are causing the symptoms without realizing it.
And since they are not actual "medical" issues, the doctors will continue to tell you that there is nothing wrong.
Don't get me wrong, there is something going on and your physical symptoms are 100% real and affecting your life, but, since it is all or mostly psychological they can run all the tests they want and nothing will ever come from it.
Have you looked into Cognitive Behavioral Therapy?
Are you on any meds?
And how old are you?