I get dizzy spells about once a week and a tingling sensation in right foot/leg that lasts several hours- what could the problem be?

Possible hypotensive. More than likely periods of transient low blood pressure, slowing the blood flow to the center of your brain providing sensation to the leg area. Other possibilities include mini seizure activity. Doubt little strokes. These don't tend to re-occur without a completed stroke. Would definitely see neurologist.
CNS Pathology. Possibility of brain stem area disease needs to be ruled out. Some times migraines may cause dizziness and tingling. If all tests are normal and dizzy spells continue, the medication for vertigo could help.