I have been having these episodes since January. They are sporadic, never know when they will appear. There is never the same time of day nor am I doing the same thing when they happen. My pressure goes as low as 48/30. I will usually just Pass out and go to sleep(a very scary feeling). The episodes will last about two to three hours with the pressure slowly going back up. I feel really lethargic the rest of the day. I wear a c-pap at night and I think that is why I have never had one during the night. I am wearing a heart monitor for a month, but cardiologist is not sure if the heart is the cause of the episodes. Any ideas or answers?