Fatigue
Fatigue may be defined as a subjective state in which one feels tired or exhausted, and in which the capacity for normal work or activity is reduced. There is, however, no commonly accepted definition of fatigue when it is considered in the context of health and illness. This lack of definition results from the fact that a person's experience of fatigue depends on a variety of factors. These factors include culture, personality, the physical environment (light, noise, vibration), availability of social support through networks of family members and friends, the nature of a particular fatiguing disease or disorder, and the type and duration of work or exercise. The experience of fatigue associated with disease will be different for someone who is clinically depressed, is socially isolated, and is out of shape, as compared to another person who is not depressed, has many friends, and is aerobically fit.1
Cancer-related fatigue is one of the most common side effects of cancer and its treatment. It is not predictable by tumor type, treatment, or stage of illness. Usually, it comes on suddenly, does not result from activity or exertion, and is not relieved by rest or sleep. It is often described as "paralyzing" and may continue even after treatment is complete. 2
What is Cancer-Related Fatigue?
Fatigue is a daily lack of energy; it is excessive whole-body tiredness not relieved by sleep. It can last for a short time (a month or less) or stay around for longer (1-6 months or longer). Fatigue can prevent you from functioning normally and gets in the way of things you enjoy or need to do.
Cancer-related fatigue is one of the most common side effects of cancer and its treatment. It is not predictable by tumor type, treatment, or stage of illness. Usually, it comes on suddenly, does not result from activity or exertion, and is not relieved by rest or sleep. It is often described as "paralyzing" and may continue even after treatment is complete.2
1. "fatigue." Gale Encyclopedia of Neurological Disorders. The Gale Group, Inc, 2005. Answers.com 26 May. 2006. http://www.answers.com/topic/fatigue
2. "Cancer Related Fatigue ." MedicineNet. MedicineNet Inc., 2001. http://www.medicinenet.com/cancer_fatigue/article.htm