### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
I am a 40 year old female, 5 6 and 120lbs. I am very active - run 15-20 miles a week, spin class 2x a week, kickboxing once a week, and tennis 2-5 times a week. I am an athletic trainer, so am also active at work. I have episodes of blackness, where (my best description) it s like the curtains are closing at a play - everything goes black, starting from my peripheral vision - sometimes the curtains close and goes completely black, but most of the time the curtains open back up before everything goes completely black. I do not faint or pass out, I just stop and stand still when it happens and wait for it to pass, which takes a few seconds usually. I have low blood pressure and was told years ago that this is what causes it. But, it happened while I was 2 miles into a run about 2 years ago. Was sent to cardiologist and underwent numerous tests, which were all negative. No answer. Blood tests indicated very high cortisol levels. My gynecologist and endocrinologist believe that is due to birth control pills, which I have been on since I was 18. My latest issue I believe is nutrition related. It just happened about 30 min ago again. I ate some watermelon and one cookie and about 10 minutes later was extremely tired. I actually fell asleep sitting on the couching typing on my laptop. When I woke up, my fingers were still on the keyboard. This has happened before, but has happened two days in a row. Yesterday it happened after lunch that consisted of a 4 inch turkey sub with lettuce, pickles, banana peppers, and mustard; watermelon; grapes; and sweet peppers dipped in hummus. Water to drink and a cookie after for dessert. Today was just watermelon (a good bit) and again one cookie. Also, I got cold and actually had goosebumps both days immediately after eating. Any ideas?

### output:

Hello, After going through your medical query I understand your concern and I would like to tell you that you require a set or cardiac and neurology investigations which includes an ECG, Echocardiography, HOLDER (ambulatory ECG) and MRI brain.  Kindly get above-mentioned tests done and consult a physician with reports for further treatment. Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. 