Fatigue: Definition

Fatigue is a vague feeling of being tired, weak, or exhausted. It is often a symptom of cancer, when cancer is first diagnosed, or when cancer progresses (Ferrell et al, 1996). It is also the most common side effect of cancer treatment. Some people with cancer have described fatigue as being “tired to the bones” or “hitting a wall.” Others say it is the most distressing side effect of cancer treatment. Fatigue is different for everyone, so it is important that the person who is experiencing it describe how he or she feels. Fatigue may cause decreased ability to work or do physical activity. If the person with cancer is easily distracted and unable to concentrate on mental work or activity, then he or she may have attentional fatigue (Winningham and Barton-Burke, 2000). Depending upon its cause, fatigue can come and go or stay constant for a while. Fatigue from chemotherapy tends to occur a few days after the treatment, peaks, and then gets better before the next treatment. Fatigue from radiation doesn't happen right away. It develops over the first two to three weeks of treatment and then increases as the treatment continues. It may last three months or more after the treatment is finished. Attentional fatigue can last up until two or three years after treatment is completed.

References:

Chan CW and Molassiotis A. The impact of fatigue on Chinese cancer patients in Hong Kong. Support Care Cancer 2001; 9(1):18-24.

Ferrell BR, Grant M, Dean GE et al. “Bone Tired:”  The experience of fatigue and its impact on quality of life. Oncology Nursing Forum 1996; 23:1539-1547.

Winningham M and Barton-Burke M. Fatigue in Cancer: A Multidisciplinary Approach. Sudbury, MA: Jones and Bartlett Publishers; 2000.