General:
* Difficulty
* Problem
* Issue
* Predicament
* Hardship
* Distress
* Mishap
* Setback
* Crisis
Informal:
* Hassle
* Mess
* Fix
* Jam
* Headache
* Bother
More specific:
* Legal: Charge, offense, accusation
* Financial: Debt, hardship, strain
* Physical: Pain, injury, illness
* Emotional: Grief, worry, anxiety
For a more specific suggestion, please provide me with some context!