My Right Thumb Sometimes Has A Tingling Or Brief Numbness

My right thumb sometimes has a tingling or brief numbness for a few minutes maybe 15 or so. Could this have something to do with the arteries to the heart. I am on 1 blood pressure medicine atenolol, and yes I' m over weight by about 50 lbs, but I have been trying to exercise by walking the park for about 30 minutes 3-4 times a week for the past 2 weeks/ Just wondering.......