This document discusses defining and measuring fatigue. It distinguishes between pathological and psychological fatigue, and defines central and peripheral models of fatigue. Acute fatigue is generally short-term and relieved by rest, while chronic fatigue is long-lasting and interferes with daily life. Fatigue is also defined in biobehavioral terms as an imbalance between resource availability and needs. The document also outlines several tools for measuring fatigue levels, including visual analog scales, multidimensional assessment scales, and checklists that evaluate subjective experience and impact on activities.

1. Defining and Measuring Fatigue
Chia Ying Li

2. Introduction
• Fatigue is a universal symptom not only
associated with most acute and chronic
illnesses, but also with normal, healthy
functioning and everyday life.
• It is one of the most common complaints of
people seen in primary health care.

3. Defining Fatigue
• Distinguish fatigue
– pathological and psychological fatigue(nurses-physical
and mental fatigue)
– central and peripheral models of fatigue
– normal fatigue as acute and pathological fatigue as
chronic(Piper, 1989-acute and chronic fatigue)
– biobehavioral

4. Defining Fatigue
Pathological and Psychological fatigue
• excessive energy consumption
• depletion of hormones, neurotransmitters
• fever, infection, anemia, sleep disturbances,
and pregnancy
• fatigue caused by weakness from illness or
treatment (such as in terminal cancer)

5. Defining Fatigue
Pathological and Psychological fatigue
• Stone and colleagues (1997) fatigue as one of
13 mood states.
• associated with stress and other intense
emotional experiences and may accompany
depression and anxiety
• a response to internal or external demands
exceeding available resources.

6. Defining Fatigue
Pathological and Psychological fatigue
• The North American Nursing Diagnosis
Association definition of fatigue is: “The self-recognized
state in which an individual
experiences an overwhelming sustained sense
of exhaustion and decreased capacity for
physical and mental work that is not relieved
by rest”

7. Defining Fatigue
Pathological and Psychological fatigue
• Ream and Richardson (1997) defined fatigue
as: “A subjective, unpleasant symptom which
incorporates total body feelings ranging from
tiredness to exhaustion creating an unrelenting
overall condition which interferes with
individuals’ ability to function to their normal
capacity”

8. Defining Fatigue
Central and Peripheral models of fatigue
• Central－CNS(hypothalamic)
• Peripheral － impaired neuromuscular
transmission at the motor-end-plate 、muscle

9. Defining Fatigue
Acute and Chronic fatigue
• (acute) generally occurs in healthy individuals,
is perceived as normal, has a rapid onset and
short duration, is usually alleviated by rest,
diet, exercise, and stress management, and has
minor or minimal effect on activities of daily
living and quality of life

10. Defining Fatigue
Acute and Chronic fatigue
• (chronic) perceived as abnormal, unusual, or
excessive, has an insidious onset, persists over
time, is not generally relieved by usual
restorative techniques, and has a major effect
on the individual’s activities of daily living and
quality of life.

11. Defining Fatigue
Acute and Chronic fatigue
• (chronic) an unknown function or purpose, as
primarily affecting ill clinical populations, as
having multiple, additive, or unknown causes,
and is often experienced with no relation to
activity or exertion.

12. Defining Fatigue
Biobehavioral
• The awareness of a decreased capacity for
physical and/or mental activity due to an
imbalance in the availability, utilization, and/or
restoration of resources needed to perform
activity
• Fatigue occurs when system is out of balance

13. Measuring Fatigue
• Fatigue Scale、Fatigue Feeling Tone
Checklist 、Symptom Distress Scale 、
Fatigue Scale、Fatigue Observation Checklist、
Piper’s Fatigue Self-Report Scale、Lee’s
Visual Analog Scale for Fatigue、Fatigue
Seventy Scale、the Multidimensional
Assessment of Fatigue

14. Measuring Fatigue
• Subjective quantification—VAS-F、MAF、
Piper Fatigue Scale、POMS
• Subjective distress—MAF
• Subjective assessment of the impact of fatigue
on activities of daily living (effect fatigue) —
MAF

15. Measuring Fatigue
• Correlates of fatigue(sleep, depression) —
VSH、POMS、POMS-SF
• Key biological parameters —blood
tests( hypothyroidism、renal function 、
anemia 、immune system)