But perhaps the biggest sign it's time to throw in the towel is that pit-in-your-stomach feeling some of us get when the weekend comes to a close ... also known as the "Sunday Night Blues" or the "Sunday Scaries."
Of course we all experience the occasional wave of dread on Sunday evening - especially after a fun weekend or when you have a particularly busy workweek ahead. In fact, a whopping 76% of American workers say they get the Sunday Night Blues, according to a Monster survey.
But if you spend every Sunday feeling anxious, depressed, or fearful - sobbing on the couch, drafting your "I'm sick" email for Monday morning - it's probably time to move on.
"Having the Sunday Night Blues can be a common phenomenon for anyone," says Lynn Taylor, a national workplace expert and author of "Tame Your Terrible Office Tyrant: How to Manage Childish Boss Behavior and Thrive in Your Job." "You're transitioning from a leisure mindset to work, with all its daily challenges. But if you're feeling trapped, hopeless, or anxious about your job for weeks or months as you face Monday - it's time to look for greener pastures."
She says writing down your feelings always adds clarity. "You don't have to produce an elaborate, perfectly crafted document of pros and cons," she says. "It's sometimes easier, more heartfelt, and effective to jot down your thoughts in a free-form way, as if you were having a conversation." For example: "I'm feeling as if I have to work at this company, or else I will ..." or, "I feel sick when I think about how my boss has been acting towards me." "As you read it, your feelings can better evolve into specific actions," she says.
Life is way too short to squander on a job that causes you prolonged misery or stress, Taylor adds. "The anxiety can spill into your weekend, and not just steal your joy - but compromise your health, too. The key thing to remember is that you do have choices. Your career future is only limited by your imagination."