There are no carbohydrates in beer or alcohol, there are empty calories, yes. but NOT carbs.
You may have very very low glucose levles in your blood, ehich would cause you to black out even after drinking a half a beer. That’s because your body needs glucose to break down the alcohol. If you are hypo hypoglycemic, (Low sugar) you will pass out, and could even go into a coma!
An endocrinologist said I was pretty close to a coma after looking at the results of a blood test, which showed TSH and T3 or T4 at the complete opposite levels of what are considered normal.