Quote Originally Posted by Seraph View Post
Трудность не проблема, нет? Проблема is for very serious circumstance, no? 'Проблема' not used the way 'problem' is used in English.
Трудность is a serious hindrance (setback) that still can be overcome. Проблема is conscious awareness that something (maybe originally thought to be трудность) cannot be resolved with available recourses or within a given timeframe and, therefore, requires some extraordinary steps, etc. to deal with.

Трудность

http://vocabulary.ru/dictionary/25/word/problema