How do I find out if I have a tumor ?

You goto to a doctor and they run tests

How about visiting a doctor and arranging for imaging tests?

Isn't that the obvious course of action?

You go to your doctor and describe your symptoms and let her take it from there.

simple, you get a CT scan

You need to consult your medical doctor.

Well a trip to the doctor would tell you if you had an MRI done.