Why does my nose bleed after a night of drinking alcohol?

Nosebleed: One possibility is that during the alcohol binge you got into a fight, and someone punched you in the nose. Alcohol can also act like a blood thinner, causing your platelets to be less "sticky" and not clot well. This is apparently more common in male drinkers than women. If you drink often, you may even have less platelets, period. http://pubs.niaaa.nih.gov/publications/arh21-1/42.pdf.

Sulfite Allergy?: Are you allergic to sulfite with subsequent nasal congestion? Sometimes excessive use of alcohol even without the allergy can lead to bloody noses.