I am 39 years old female.6 years ago I had these strange symptoms and since than my health is going dawn.I have those attacks ,it feels like something is choking me around the neck with severe dizziness and nausea.IT last for about 30 min and then headache start.In the mean time I feel very nauseated and dizzy whit headaches every day.Now I have new symptoms pain in my chest around the heart which goes to my left hand when i was sleeping i was awakened from this severe heart beat it felt like my heart will explode also squeezing in the chest,with dizziness felt like i will foll from the bed,i had to go to the bathroom it felt like diarrhea but it wasn't and nausea I took gravel and Tylenol felt better a little bit,and in the morning I had headaches with pain in my shoulders.Ive done almost every possible test city scan ,MRY,blood work,urine test,ECG,sinuses,eye test,allergy test,ears and so on I have the feeling that somebody is missing something and everything come normal. anybody have an idea what could be