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

### input:
About a month ago I had a sudden onset of something that was foreign to me up until that time. It was early evening and I was beginning to feel tired. All of a sudden I got this queezy feeling in my gut, and then a feeling of very hot spread throughout my body. My skin felt like it was on fire. I broke out into very profuse sweating, and quickly soaked my clothes. I got lightheaded. Being a mild diabetic, I took my blood sugar level and it was normal. Also, I have high blood pressure and have blood pressure machine. My blood pressure was within limits. After about 45 minutes the symptoms began to subside. After an hour I was feeling better but completely wrung out . I kept getting these symptoms every evening, albeit moderately, for a couple of weeks. For another couple of weeks I got the symptoms, albeit mildly, sometime during the day at differing times. Now, I get the symptoms mildly every once in awhile. The first set of symptoms really scared me and I almost called the ambulance. I would like to find out what this might be because the next time I get a severe set of these symptoms I may black out, and I live alone. I forgot to say that I am a 65 year old male who has had 7 lower spine surgeries and a knee scope surgery. I had a TENS unit surgically implanted in my lower back and right buttocks, but it had to be removed after a couple of months due to very severe staph infection. It took a lot of strong antibiotics(Vancomycin) to get that under control. The last back surgery was done at KU Med. Center, Kansas City, where they opened up my abdominal cavity to get in and put bone wedges in between 3 vertebra, put that all back together and sutured up, turned me over, and opened up the posterior of my lower back to put 3 sets of screws in the same 3 vertebra and tied them all together with rods, sutured that up and called it good.

### output:

Hi, I understand your concern and would explain that it is necessary performing a comprehensive differential diagnosis between different possible causes that may lead to this clinical situation: thyroid gland dysfunction, possible cardiac arrhythmia, orthostatic hypotension, low blood perfusion to the brain, etc. For this reason, I would recommend performing some tests to investigate for the possible causes: -a Doppler ultrasound of the carotid arteries - thyroid hormone levels for possible thyroid gland dysfunction- blood electrolytes for possible imbalance- an ambulatory 24-48 hours ECG monitoring in order to investigate for possible cardiac arrhythmia. You should discuss with your doctor on the above tests. Hope I have answered your query. Let me know if I can assist you further. 