I ran a twelve mile run a couple of days ago. 5 hours later I started to feel funny. Felt a little unstable standing, started seeing spots, felt nauseous, started shaking. Went to Er. Said I was dehydrated. My sodium was a tad low and I have had hyponatremia earlier this year. I had two electrocardiograms that were perfect. No chest, shoulder, arm, jaw or neck pain. They did a test and I had a very high troponin level. Two cardiologist at other larger hospitals would not take me. One even questioned the ER doctor on why he did the test. He said it wasn t a heart attack. I have read that strenuous exercise can cause a high troponin reading. Is this true? I have been scared to death.