What Causes Dizziness And Nausea?

Good afternoon, a little background... I awoke this morning and felt fine and apart from what I ve been experiencing this morning - still (sort of) feel fine. I am a 57 yr old female, 5 4 overweight (approx 180lbs) and a smoker. I awoke earlier (about 10am). While sitting outside, waiting for my dog to do her business, I was hit by a wave of dizziness (a slight graying out feeling), nauseousness and waves of what I can only describe as a heatwave travelling head to toe. I don t recall my heart racing (but it might have been)... there was no chest pain. I took several deep controlled breathes until the feeling passed and I continued on with my day. Since then, and right now in fact, I have continued to have this feeling (about 8 times in 5 hours). It s like heat & a tingling sensation radiating through my body, mostly arms & legs and lower back - face will feel flushed, I get nauseous and dizzy. I continue to do controlled breathing through this until it passes (about 5 secs). However, I have this incredible headache now as well and the ringing in my ears (which I ve had for years) is worse. This feeling has happened about 8 times since I awoke. I have checked my pulse and it appears to be within the reg limit at about 68-72 beats/min. Apart from these oddities I feel fine. 9 times (just now).... I don t know whether I should visit the emerg or not..... I m a little scared..... Help/Advice?