It's an unfortunate fact that more than 50% of Americans identify as being unhappy at work. Yet unhappiness takes on different forms. You might, for example, be displeased about certain aspects of your job, like the long hours you're frequently forced to work, or the stingy benefits your company gives out. But just because you're dissatisfied in some regards doesn't mean it's time to up and quit.

On the other hand, there are certain situations in which leaving your job almost universally makes sense. Here are a few such scenarios.

1. You haven't been promoted in years

Different companies have varying procedures for dishing out promotions. Some hand them out based on length of employment. Others base the decision on specific skills or accomplishments, as opposed to tenure. Regardless of your company's policy, if you've been at your job for a number of years without a promotion, it's time to move on -- especially if your core responsibilities also haven't evolved since you first got hired.

Stressed out coworkers

IMAGE SOURCE: GETTY IMAGES.

How long is too long to stay on board without a promotion? It varies based on the industry or even the company. Some experts will tell you to move on after two or three years without a title change or otherwise notable degree of advancement; others might advise waiting a bit longer. But pretty much no matter where you work, if you've been on the job for five years with no promise of a promotion, it's time to take your skills elsewhere.

2. You're unhappy with your compensation

It's one thing to accept an entry-level salary when you're fresh out of college with limited working experience. But if you've been at your job for quite some time and are wholly dissatisfied with your compensation, it's time to move -- especially if you've actually asked for a raise, only to have that request repeatedly denied.

These days, you have the best chance of snagging a sizable salary boost by getting hired at another company, ideally at a level that's higher than your current one. If you're convinced you're being undercompensated based on your experience, industry, and skill set, it's time to dust off that resume and start networking your way to a better opportunity.

3. You're constantly stressed or burning out

It's natural to experience periods of work-related pressure, whether due to quarter-end deadlines or major product launches. But if you come to find that you're constantly stressed out to the point where it's harming your overall well-being, then it's time to look for a job that won't wreak as much havoc on your mental state.

The same holds true if you're currently suffering from a prolonged state of job-related burnout. And no, "burnout" is not just a buzzword thrown around by disgruntled employees; it has an actual medical definition. According to the Mayo Clinic, burnout involves "a state of physical, emotional, or mental exhaustion." And if you find yourself experiencing burnout, you're not alone. In a 2015 study, over 50% of employees felt they were experiencing job-related burnout, which can be caused by a variety of factors, such as consistently long hours or forgone vacation. If you don't see a solution to said burnout in sight, it's time to find a job that's less likely to jeopardize your sanity.

Picking up and finding a new job is easier said than done, but if you're truly miserable in your current role, and your company takes no steps to address your major pain points, then you're better off putting your resume out there and working on those applications. You deserve a job that's rewarding on both a mental and financial level, and if your current role just isn't doing that for you, don't hesitate to move on to bigger and better opportunities.