Crisis (noun)

1. A time of intense difficulty, trouble or danger.
2. A turning point in the course of something, especially a critical point in the progress of a disease.
3. A state of affairs in which a decisive change is impending, especially when the change is unwelcome.
4. A state of emergency or a decisive moment in a situation.

Origin:

From latin crisis ("a turning point in a disease"), from greek κρίσις (krísis, "decision, judgement, crisis"), from κρίνω (krínō, "to separate, decide, judge").

Examples:

1. The company is in a financial crisis.
2. The country is facing a political crisis.
3. He had a crisis of faith.
4. The country is in the middle of an economic crisis.
5. She had a midlife crisis and changed her career.