Just as your body needs vitamins and proteins, certain “nutrients” are also essential to sustain high motivation, including getting rewards ? or motivational“wins”? or good work and feeling that you have control over your work life. In other words, you must feel that you can influence what happens to you by what you  do.

Motivation is determined largely by what happens after you act. For instance, you get a bonus for making a big sale or your boss praises your idea. If your actions bring no rewards, your  motivation to perform lessens or burns out. Demoralizing work situations similar to the ones below are key contributors to job burnout.

The Critical Boss
No matter how hard you try or how well you do, you boss always find a nit to pick. Eventually, you feel unable to satisfy this kind of boss.

The Incurable Client
If you’re in a service job, such as social work, you probably have a large caseload of clients with nearly impossible problems. No matter how hard you try, how much you give or how much you care, the drug addicts continue to use drugs, the welfare recipients can’t get work and the delinquents end up back in juvenile hall.

Lack of Recognition
Your good work often goes unnoticed. You may be in a civil-service job, where promotions are based on seniority and not performance. Two other forms of lack of recognition include:
 

Inadequate pay:When you work hard but feel underpaid, you may think that your efforts aren’t being adequately rewarded.

Underemployment: If you have high aspirations and spent years in college preparing for work but you’re stuck in a low-level job, you may feel that no one has recognized your talents. Baby boomer who must compete with millions of others to squeeze into a narrowing pyramid of higher-level jobs are particularly prone to this dilemma.

Ambiguity
If you don’t know what’s expected, it is difficult to feel confident that you are doing the right thing in the right way. Chaotic and ambiguous work situations are common in rapidly expanding high-tech firms. Examples of ambiguity are:
 

Lack of Information: You don’t have enough information to do your job properly. As a result, you may be working hard on the wrong thing.

Lack of clear goals: Jobs in rapidly expanding organizations, entrepreneurial operations and poorly managed departments often don’t have well-defined responsibilities and clear-cut goals. Without clear goals, you have no target to shoot for.

Tasks Without End
Your “in basket” is always full, no matter how long or how hard you work, or you face a seemingly unending line of customers, who eventually become faceless. This a problem with any job that has no natural beginning and ending point.

No-Win Situations
Your job may have incompatible demands so that no matter what you do at work, someone is dissatisfied.Perhaps you report to two bosses: One wants speed while the other wants quality. It may not be possible to produce both. Or you may work with several departments; marketing wants one thing, manufacturing another.
 

Conflicting Roles:You’re expected to be star employee, supermom and superwife; your company wants you to travel for business and your family wants you at home.

Politically Incorrect Jobs: If  you work in a politically sensitive field such as police work, IRS investigation or military research, you may experience value conflicts: You believe in what you are doing and you strive to do a good job; yet you are criticized for the work you do.

Work Overload
A lot of work in and of itself will not burn you out as long as you feel you can control what happens and you receive adequate wins. You may be very tired, but you feel motivated. However, work overload in one of the above categories is a setup for burnout.

Bureaurcracy
Organizations are based on the military model of the hierarchy and chain of command which is desgined to make sure that no one person has too much power.  But having power, a sense of control over one's life, is necessary for healthy functioning.