My first thoughts are that one would not. A medical doctor of the western traditions is trained to not accept astral projection as a logical devise. They will assess hallucinations, chemical imbalances and such like. If you cannot accept that these are the basis of your experiences of astral projections, they will simply refer you to a psychiatrist and a drug cocktail to balance your system.
Now don’t get me wrong, you may have experienced astral projection. I’m just saying you do not get to keep it as a spiritual event when you talk to a medical doctor, especially one trained in western medicine.
So what you are really asking? How to stop having these experiences, or how to hold these experiences as spiritual and function as normal in society?
If you want to stop having these experiences, then just tell your doctor that you are having these experiences and ask for help in finding the cause so that you can stop.
If what you want is the second, then you need to do more research outside the mainstream medicine world.