I have episodes where i'll be sitting and or walking and all of a sudden i'll feel extremely dizzy. i've had blood test taken and i've been to an ent but nothing comes up. i was told that previously it was vertigo and caused by stress?

Keep working with Dr: A person who has symptoms that come and go can help her doctor by writing down the symptoms on a calendar diary, including when they happen, how long they last, what makes them worse, what makes them better, any medications or illegal drugs used, etc... Several visits to one's primary care doctor may be needed to sort out the symptoms. One should be sure to exercise to keep the body resilient.