Yesterday i tripped and hit my head while walking up the stairs. later i got drunk but i recall the events before/after. concussion or hangover?

Have no idea: because you haven't listed any symptoms of either condition. Getting drunk after a head injury doesn't sound like its using your best judgement, or even just common sense. If you have symptoms of a concussion (dizziness, imbalance, nausea, vomiting, headache, or any neurological complaints) see your doctor. A hangover is marked by nausea, vomiting, lethargy, and can have headache. See your Dr.