Travailler trop
You can also use these expressions:
* Se tuer au travail: This literally translates to "kill oneself at work" and implies working extremely hard, almost to the point of exhaustion.
* S'épuiser au travail: This means "to exhaust oneself at work" and suggests working so hard that you are becoming tired or worn out.
* Faire des heures supplémentaires: This translates to "do overtime" and refers to working beyond your regular hours.
* Être accro au travail: This means "to be addicted to work" and implies that you are constantly working and can't seem to stop.
The best expression to use depends on the context and the level of intensity you want to convey.
For example, you might say:
* Je travaille trop et je suis épuisé. (I'm working too much and I'm exhausted.)
* Il se tue au travail pour réussir. (He's killing himself at work to succeed.)
* Elle est accro au travail et ne prend jamais de vacances. (She's addicted to work and never takes vacations.)