I would like to better understand the affects on the human body of a loss of consciousness from a lack of blood supply to the brain and the treatment required after. I am mainly looking at the blocking of the carotid arteries as done during a [sleeper hold][1]. I have broken this down into the following parts:

 - If the blood supply goes back to normal after a loss of
   consciousness, is consciousness regained automatically or is CPR or
   other steps needed in addition for consciousness to be regained?
 - If the blood supply is restricted even after a loss of consciousness, will this affect how easily consciousness can be regained? Eg. is there risk of a more severe level of unconsciousness such as a coma, can consciousness still be regained automatically be allowing blood supply back to normal at this point or will CPR or other steps always be required? This goes to the point that sleeper holds are generally recommended to be only held for a maximum of 10-15 seconds, I would like to know the possible medical reasons for this and consequences of going beyond this point.
 - Once losing consciousness what would generally be the treatment/steps attempted to regain consciousness?
 - Once consciousness is regained via the treatment/steps above, would there need to be any follow up treatment and if so how long would the patient generally need to stay at the hospital for such a treatment or would they be discharged once conscious again?


  [1]: https://www.wikihow.com/Do-a-Sleeper-Choke-Hold