I agree with the previous posters who recommend you get a check up. It could be any number of things. Do you get any other symptoms with your dizzy spells? Headaches, nausea, blurred vision, ringing in the ears, etc? It can be migraines, it can allergies, it can be heat exhaustion, or possibly something more serious. It's better to get a doctor's opinion and go from there.
hi goldie, I agree with VaniDavila. There could be so many reasons. It could be dehydration, not eating enough, stress. low bloodpressure, low sugar or a symptom of something...so many things. Seeing a doctor would at least narrow down reasons. I am hoping everything works out for you.
Oh just a P.S. :Always get a second opinion. Never take one opinion as a certainty.
Have you seen your doctor? I really recommend you see your doctor first!