There are a number of signs that it is time for a career change. Many people work at certain careers for a long time because they think it is right for them or they are just making very good money. But when interest wanes for a particular job, working that job can get very bad very quickly and your work and attitude will most likely suffer. So know the warning signs of when you need to change careers before you really begin to resent both your job and your life.
Does just getting up and going to work sound awful to you? Are you not entertained in aspects of your job that you once were? Are you counting the hours until you can get away from work every day? Then you are probably burnt out on it because you have been doing the same job with few real mental breaks for a set period of time. This exact amount of time can vary for many people, but since you can't stop working one career while your mind relaxes, this burnt out feeling will only get worse unless you change careers, quit or are allowed to take an extended vacation.
Some careers hit brick walls, as you have risen steadily in your job and can't really rise any higher unless you want to dedicate another decade of your life to it. While the pay may be good and you have a position of authority, knowing you aren't going to be able to move up in your career for a long period of time either means you need to work a similar career for a different company or just change careers altogether. Obviously, this varies from company to company.
If you loathe your job and the people in your job, then you definitely need a career change. The ideal careers are the ones that you get real joy out of doing every single day, the ones that are your proverbial passion. However, those are hard to make a career out of and most people end up working jobs that they get some happiness from, make money at but don't love. However, if you find yourself hating your job, then you need to quit, as it is bad for your work and your mental mindset as a whole.
If you've always wanted to be a singer, for example, and not work in a corporate office, then maybe it's time you follow your dream and take the chance to be a singer. It depends how strong this passion is and how much it distracts you from your job, of course. However, if you are thinking about your passion every day and wishing you were doing it, maybe you should, or at least do something that utilizes an aspect of this passion for work.
The career you have might take up to much of your day when you need to be at home with your new baby or you may have inherited some money, allowing you to work less. All of these factors can play in to you making a career change, as life doesn't follow the common career path.