After 5 years of not being able to see a doctor. I finally went to a new one, as I moved to a different state. I explained her all my symptoms that have been coming and going over the last few years, which are as follows: often headaches, sharp stabbing pains in different parts of my body that last only a few seconds but can happen multiple times a day, tunnel vision which leads to loss of vision for a few seconds, dizziness, nausea, constant sweating, cannot sleep through the night, loss of balance, blacked out a few times to the point where I hit the floor, unintentional weight loss (went from 121 to 115 in a week). She immediately started tests. First was blood test, then a CT scan, then a 3 day ambulatory EEG/EKG, and now she wants me to do a 2 day echo exam with holter monitor; since the previous tests came back "negative." She does not explain to me what negative means, what they were looking for, or what she expects the next test to show that the previous one didn't. Can someone please tell me if I am going down the right track with getting this next test or if it is time to find a new doctor???