The reasons for wanting to switch careers range from the practical to the idealistic. Most likely your list will include many of these factors:

• You have a chance to escape a fast-lane urban lifestyle.
• Your job and career no longer interest you; maybe they bore you.
• The idea of 20 more years in the same career has lost its appeal.
• You would like to work in a different part of the country.
• You’ve been downsized, fired, canned, pinked-slipped, or whatever you—and your former employer—want to call it.
• You see little room for future growth in your current career.
• You feel a “calling” to do something else in life.

You want to be your own boss.
You want to convert a hobby into a full-time occupation.
• A “glass ceiling” has frustrated your corporate-career plans.
• You want to tap into the more dynamic growth that is expected in other careers.
•You don’t want to work so hard.
You want to blend two or more careers into a single career.
• You realize that you jumped into a first career without really thinking or were pushed into it by your parents.
• You have inherited or are about to inherit a tidy sum. Some economists predict that trillions of dollars will change hands from parent to child over the next 20 years. Along with this windfall will come the possibility of greater economic freedom and an ability to change careers without suffering a serious
financial setback.
• You want to “make a difference.” Regardless of the position or title they hold, many people feel that they are only cogs within their organizations, and they want to do work that they view as important—for their own sake and, often, for the sake of others.

Source : Robert K Otterbourg. Switching Careers. 2001