More U.S. workers are dissatisfied with their healthcare benefits and chances for promotion in 2011, than they were in 2008, according to the annual Work and Education poll by Gallup. The dissatisfaction with healthcare benefits increased 11 points in the past three years -- the biggest change registered in the poll of 489 adult workers -- followed by a 7-point increase in dissatisfaction over the potential for promotion at work.

The following job issues caused the most dissatisfaction overall for this year:

Employee Dissatisfaction in 2011

34 percent: On-the-job stress

30 percent: Health-insurance benefits

30 percent: Compensation

28 percent: Employer retirement plan

26 percent: Chances for promotion

20 percent: Vacation time

19 percent: Recognition for work accomplishments

18 percent: Job security

17 percent: Amount of work required on the job