Work
A person's job can be a source of stress, especially because of the amount of time spent there each week. The Mayo Clinic states that an overwhelming workload or a difficult boss can increase the level of stress. If a person does not like her job, has a long commute or has altercations with her co-workers, she can experience even more stress. Helpguide.org notes that on the Holmes-Rahe Life Stress Inventory, getting fired from a job is the eighth most stressful life event.
Self-Generated
Stress also can be caused by a person's inner thinking. For example, unrealistic expectations and perfectionism can make events in which a person did not realize his ideals even more stressful. Pessimism and negative self-talk also can cause stress.