I was told, yet again, that thal minor is asymptomatic.
Few things I notice about myself.
Heat/ Dehydration makes me feel worse, like I have no blood left. My Hgb is always 9.
Exercise/exertion/stress makes me feel worse too. 
Allergies/infections - I get a lot of them which are not always obvious. They pull me down completely.
All of the above can lower my BP below 90/60.  Feels like I cant function at all.
On a healthy day, I might just feel good at my hemoglobin of 9. 
A note about iron deficiency.
My entire life I was made to take iron pills, with no improvement in my hgb or ferritin. The only thing that happened was that I developed more medical problems.  
Now some logic has set in.
If at all an anemic thal minor has iron deficiency too, without iron supplements, the hgb should keep getting lower - as is the case with non-thals who can even get as low as 5-6-7. The fact that it maintains at 8-9, probably could mean there is no iron deficiency, and that only thal minor is to blame.
makes sense?  :-)  :-)