I agree it can be a lot of things. How high is it?
Hi yachtie and welcome to the forum.
Increased basophils or basophilia (which is somewhat uncommon) have a number of possible causes, some of which are:
Inflammatory processes, hormonal (hypothyroid,high estrogen),
viral infections, hemolytic anemia, Hodgkin's Lymphoma, some types of leukemia and other.
I hope this helps, but please note that this is not intended as a substitute for medical advice.
Best wishes.
Niko