Some of the ways you could damage your career are obvious - poor work performance, shouting at your boss and stealing from the company are all pretty well-known career-harmers. But there are less obvious things you might be doing that can also damage your career without you realizing it, and they're worth paying attention to.
Here are five ways you might harm your work progression that might not be so obvious.
1. Staying too long at one job. You might think that loyalty to an employer would be valued, and it is, but there's also a point where staying too long at one company can raise questions for future prospective employers about how you'll adapt to new environments. Somewhere north of eight years and south of 20, many employers start worrying that you'll be stuck in one company's way of doing things, won't have been exposed to a wider variety of practices and cultures, and thus won't adapt easily.
(You can combat this, however, by demonstrating adaptability: Showing a progression in responsibilities and job titles, and finding other ways to show that you're flexible, open to change and don't have an insular viewpoint.)
2. Being too good at something you don't like. In general, the better you are at something, the more you'll be asked to do it. Of course, that doesn't meant that you should purposely do a bad job at work you don't enjoy - that won't accomplish anything helpful for your career either - but it does mean that you should focus on becoming best at the things you do like to do, so that you're sought after for those instead.
3. Not speaking up when you disagree with the boss. Sure, some managers just want to be surrounded with yes-men, but working for a manager like this isn't a good way to build your career. You want to work for good managers, and good managers want to work with straight-shooters who they can count on for the truth. That doesn't mean that you should push back on every minor disagreement, of course, but it does mean giving your candid opinion when it matters.
Part two of that is being able to accept it if the eventual decision doesn't go your way. When your boss knows that you won't sulk if she ultimately makes a different decision than you're advocating, it's much easier to welcome your input.
4. Recommending someone for a job as a favor to them. When you provide a positive reference for someone, you're putting your own reputation on the line to vouch for them. You're saying, "I consider this person's work excellent." If the person's work isn't actually excellent, it will reflect badly on you and your judgment - and can really harm your own reputation. After all, if Jane's work is awful and you said it was great, what does that mean for your own work and quality standards?
If you want to help someone out but can't honestly recommend his or her work, help in other ways: Send job leads, give feedback on his or her résumé and point him or her to helpful resources. But don't sacrifice your own reputation by giving a reference you can't stand behind.
5. Not going to workplace social events, ever. Not everyone loves office social gatherings, and that's fine - but the higher up the professional ladder you go, the more you'll be expected to at least make an appearance at some. In many companies, habitually skipping these events can signal that you're not interested in building relationships with colleagues, and can even damage your career. It might be unfair or unreasonable, and it's still up to you whether you go or not, but beware that never showing up might come with a price tag.
Alison Green writes the popular Ask a Manager blog, where she dispenses advice on career, job search, and management issues. She's also the co-author of Managing to Change the World: The Nonprofit Manager's Guide to Getting Results, and former chief of staff of a successful nonprofit organization, where she oversaw day-to-day staff management, hiring, firing, and employee development.