This is a common tricky question in the USMLE and it's usually difficult to distinguish.
Always look for clues, the love to give clues in USMLE:
Clues going with Mallory Weiss Tear:
- Sudden onset (like the last few hours)
- Severe retching (very important buzzword), so it's actually the retching and vomiting that produces the tear and the bleeding.
- Patient might be bulimic not alcoholic.
- Usually a trivial problem and requires no treatment.
Clues going with variceal bleeding:
- End-Stage-Liver-Disease (Cirrhosis) Stigmata, such as spider nevi, palmar erythema, ascitis, ..etc
- No immediate warning signs before (I mean no retching or something, it just comes all of a sudden.
- Large volume of bleeding (to the point of shock usually) and a recipe for impending death in alcoholics.
Note that both of them are usually painless vomiting.
The real dilemma is when Mallory Weiss progresses to Boerhaave Syndrome which is like varices is also lethal