I have had a few episodes in which, during sleep, I suddenly feel very unwell, and then swoon -- afterwards, still in and out of sleep, I feel disoriented and it takes a while before full consciousness and memory returns. What is this?
Hi, is there any triggering factor for the sleep disturbance you are having, do you get any horrifying dreams on such days. stress either physically or mentally can also be the cause. do you work late nights. Its better you consult your Physician for investigation.
Have you got your blood pressure and sugar checked? Well the possible explanations are - either you have a hypoglycemic episode at some nights; or you have low blood pressure while lying down/ sporadically on some nights; or you have to also observe whether you have these symptoms on nights you have had a late meal/ heavy meal/ missed meal.
So you should get the relevant investigations done - blood sugar level - fasting and post prandial; blood pressure monitoring - while sleeping if possible; blood sodium levels ( serum electrolytes) and consult a physician simultaneously.