I am seeing a hematologist oncologist for anemia problems.  I have other health problems that led my GP to do an MRI and my unusual red blood cells showed up.  I have been poked and prodded and had many tests done.  At my appointment today the nurse practioner said that one of the blood tests showed that I might possibly have thalessemia.  I have heard this term used before when I had problems during my pregnancies (many years ago)..  I have always been "anemic" but got very anemic this past spring.  My spleen has been enlarged for some time - off and on.  Blood tests done come back okay sometimes, but elevated or low at others.  I still get my menses but not very heavy and I'm not bleeding from anywhere else - believe me I've had enough tests to confirm that!  I am exhausted, forgetful, dizzy, tingly in hands and feet (this might be because of my back).
So is it possible for me to be diagnosed with Thalessemia in my forties?  Why didn't I see it before now?  What blood tests show that thalessemia is a definitive diagnosis?