The most common cause of choking in your sleep is the relaxation of your necks soft tissues.
This relaxation of the necks soft tissues can lead to your throat collapsing some and causing you to choke in your sleep.
It's usually not a cause for concern unless it happens to frequently.
However choking in your sleep can be serious in some cases and yes it is indeed possible to choke to death in your sleep.
That is if you actually have Sleep Apnea which could be causing you to choke in your sleep so it would be best to get checked out by a doctor and let them know about your issue of choking in your sleep.
Normally you should not be choking in your sleep and it would be best to get checked out by your doctor for it.
If you have sleep apnea you need a sleep apnea CPAP machine to breathe properly through the night or you could die.