Three weeks ago, I got hot all over but mostly above the chest , then I got extremely lightheaded and felt like I was going to pass out. Called 911 thinking I was having a stroke (I had a cerebral infarction right after chemo two years ago). At ER they found no sound of any new stroke and other than my blood pressure being high (expected in the hospital and scared), there was no sign of a problem. The next morning At first it only happened when I was sitting down between 9-11 in the morning. I have given up caffeine thinking perhaps that was the culprit. Also started eating a light breakfast as soon as I get up thinking perhaps low blood sugar . Always I could get up walk around and the feeling would go away. Then I started letting light headed when I started to doze off or when I was asleep (it would wake me up) during the night. Lately, I ve noted that my lower back where it transitions to the buttock always begins to hurt just before I have an episode or if I get up in the morning with a lower backache, then I get weird hot/almost lightheaded feelings all day. I ve had two EKG s and a heart halter for 48 hours. All was well. I don t know where to go from here. My doctor thinks it s anxiety so I started taking Xanax. calmer but it hasn t stopped the backache/hot spell/light headedness. I also experience shortness of breath and what feels like rapid heartbeat although my pulse only seems slightly elevated. I can walk on a treadmill with no impact although I do not walk if my lower back has been hurting. Any ideas? What type of specialist would I even go to for this? I do not get lightheaded when I bendover, standup, etc...only when I m sitting or when I m asleep.