What Is Fatigue?
Symptoms and Possible Causes
Patient and Caregiver Education
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Fatigue is a feeling of weariness, tiredness, or lack of energy that varies in
degree, frequency, and duration. Everyone has experienced normal fatigue, which
improves with rest. Chronic fatigue associated with a disease or treatment of
a disease does not improve with rest and can seriously affect a person's ability
to function and quality of life. Fatigue can impact quality of life in many different
ways -- physically, emotionally, socially, and spiritually.
Acute vs. Chronic Fatigue
Acute fatigue has a recent onset and is temporary in duration. It is usually related
to excessive physical activity, lack of exercise, insufficient rest or sleep,
poor diet, dehydration, increase in activity, or other environmental factors.
Acute fatigue can be a protective body function, alerting a person to rest. It
is anticipated to end in the near future, with interventions such as rest or sleep,
exercise, and a balanced diet.
Chronic fatigue persists, and recovery is not quickly anticipated. Chronic fatigue
may be associated with numerous illnesses, such as cancer; AIDS; heart, lung or
kidney problems; multiple sclerosis; and other medical conditions. Fatigue can
also accompany psychological problems, such as depression, or result from the
use of medications.
Fatigue symptoms are common, yet underrecognized, in cancer patients. Fatigue
experienced by cancer patients can result from the course of the disease, preexisting
physical or psychological conditions, effects of medication, or lack of exercise.
Fatigue may also result from treatment such as surgery, chemotherapy, and radiation
Fatigue from cancer surgery can last for weeks or months, and may be caused by
anxiety as patients prepare for surgery, as well as the pre-admission testing
for surgery. Pain after surgery, the effects of anesthesia, sedatives, or analgesics
may also cause fatigue.
Fatigue from chemotherapy affects most patients, lasting for one to two weeks
following treatment then decreasing gradually. Fatigue as a result of radiation
therapy affects almost all patients and may worsen during the course of treatment,
peaking at 4-6 weeks. Fatigue may lessen after radiation therapy is completed
but still continue for weeks or even months. Many patients undergoing interferon
or interleukin therapy also experience fatigue.
Patients may discuss adjusting therapeutic regimens with their doctors to relieve
fatigue symptoms. Delaying chemotherapy treatments for 1 or 2 days to attend important
life events, or changing the time of their treatment, may be considered.
Common Fatigue Symptoms
Fatigue is generally defined in terms of symptoms that occur over time, cause
distress or impair function, or are likely to result from disease or treatment
of disease. The following symptoms, which vary from patient to patient, are
associated with fatigue:
|| Diminished energy disproportionate to activity, causing distress
||Diminished activity associated with lower physical or intellectual performance,
e.g., lack of focus, short attention span, memory problems
|| Diminished motivation, interest in activities
|| Exhaustion, apathy, lethargy
|| Generalized (whole body) weakness or tiredness
|| Sleep abnormalities
|| Irritability, impatience, sadness, changes in mood
Possible Causes of Fatigue
Though little is known about fatigue prevention and treatment, fatigue may be
related to a variety of medical and physical conditions and psychosocial factors.
Fatigue can be caused by anemia or associated with major organ dysfunction, including
severe heart or lung disease, kidney failure, or liver failure. Hypothyroidism
(insufficient production of thyroid hormone) and adrenal problems, even if mild,
can cause fatigue. Neuromuscular disorders, malnutrition, infection, dehydration
disturbances can also be associated with fatigue, as well as sleep disorders,
immobility and lack of exercise, chronic pain, or the use of centrally-acting
drugs (e.g., opioids). Psychosocial factors associated with fatigue are anxiety
and depression, stress, and those related to the reactions of others to the fatigue.
How Health Care Providers Assess Fatigue
Assessment of fatigue begins with a detailed description of
its history, development, symptoms, and causes. This information is acquired
from the patient's self-report, medical history, physical examination, and review
of laboratory tests such as a complete blood count, thyroid function, and imaging
studies (CT or MRI scan).
The onset of fatigue, course of the symptoms, severity or intensity, level of
distress, and degree of interference with daily activities (e.g., grooming,
shopping) should be addressed. Factors that relieve fatigue or make it worse
should also be examined. These factors may be emotional (moods, etc.), social
(relationships with family and friends), and psychological (effect on thought
process). These areas can be assessed using a verbal rating scale: none, mild,
moderate, and severe; or a 0 to 10 scale (where 0 means no fatigue and 10 means
the worst fatigue imaginable). One scale is usually adopted and consistently
The treatment of fatigue includes identifying and managing the underlying
cause and using a variety of interventions, including medication; education;
exercise; sleep hygiene; stress management, and nutrition.
Anemia (below normal levels of red blood cells) can be a major factor in cancer-related
fatigue. Lack of red blood cells and oxygen in the body creates an energy deficit,
causing tiredness or fatigue. Blood transfusion therapy, as well as recombinant
human erythropoietin (a hormone produced by DNA technology), is used to treat
anemia. Erythropoietin stimulates bone marrow to produce red blood cells, thereby
increasing the number of red blood cells in the body.
Adjusting Current Medications
Patients on medication who complain of fatigue may need their drug regimens
reviewed or adjusted by their physicians. Centrally-acting drugs that are not
essential may be eliminated or reduced (e.g., antiemetics, hypnotics or anxiolytics,
antihistamines, and analgesics). If opioids are taken for controlling pain,
dosage reduction is done cautiously to see whether fatigue improves without
making the pain worse.
Commonly Prescribed Medications
Drug therapy for treating fatigue associated with medical illness has not been
evaluated through controlled studies. Some doctors consider the use of psychostimulants
such as methylphenidate and pemoline. These drugs are often used to treat opioid-related
cognitive impairment and depression in the elderly and medically ill.
Sometimes low-dose corticosteroids
(e.g., dexamethasone or prednisone) are used in the treatment of cancer-related
Amantadine has been used for many years in the treatment of fatigue due to multiple
An antidepressant drug may be used to treat fatigue due to clinical depression,
preferably one of the serotonin-specific reuptake inhibitors, secondary amine
tricyclics, or buproprion.
Non-Drug Interventions to Manage Fatigue
In addition to medication, non-drug interventions may be used to manage fatigue.
Patients and caregivers can be helped to understand the nature of fatigue symptoms,
treatment choices, and expected outcomes through education and counseling. Patients
can be prepared to anticipate fatigue as a normal part of the course of cancer
and its treatment. Patients can be taught energy
conservation and restoration strategies while undergoing these treatments.
The following are print resources in Adobe Acrobat(tm) .pdf format for patient
and caregiver education:
Exercise may be beneficial in relieving fatigue. The exercise program should
be tailored to the individual according to age, gender, physical and medical
condition. Exercises should involve rhythmic and repetitive movement of large
muscle groups (walking, cycling, or swimming). These exercises should begin
gradually, several days a week, and not be performed to the point of exhaustion.
Some contraindications to low-intensity exercise include cardiac abnormalities,
recurrent or unexplained pain, and onset of nausea with exercise.
Change in Activity and Rest Patterns
Using a diary to assess fatigue may identify specific activities that increase
fatigue. Patients can record changes in energy levels, and this information
can help to modify, schedule, or pace these activities throughout the day.
Naps should be taken in the morning or early afternoon; late afternoon or evening
naps might interfere with sleep at night. Basic sleep
hygiene principles, such as a specific bedtime and wake time, noise and
light reduction, diversional activities (e.g., music, massage), avoidance of
stimulants (e.g., caffeine, nicotine, steroids, methylphenidate) and central
nervous system depressants (e.g., alcohol) prior to sleep should be employed.
A specific wake time helps to maintain a normal sleep-wake rhythm. Consistent
exercise tends to improve sleep and promote deeper sleep when done at least
six hours before bedtime.
Stress Management and Cognitive Therapies
Using stress reduction techniques or cognitive therapies (e.g., relaxation,
deep breathing, hypnosis, guided imagery, or distraction) can promote coping
skills and relieve stress.
Coping skills such as seeking more information about the illness and its interventions,
planning and scheduling activities, delegating tasks, and developing solutions
to daily problems associated with fatigue are helpful to patients.
Mental fatigue may be relieved by activities that conserve and restore mental
capacity, such as decreasing noise and distractions while trying to concentrate,
walking outside, gardening, and other environmental activities.
Adequate Nutrition and Hydration
A balanced diet that combines adequate caloric intake, e.g., grains, green vegetables,
legumes, and iron-rich foods, can help maintain energy levels. Adequate fluid
intake can prevent dehydration and hypotension, which can intensify fatigue
symptoms. Regular exercise may improve appetite and increase nutritional intake.
Adapted from Assessment and Management of Cancer-Related Fatigue by Russell
K. Portenoy and Christine Miaskowski.
For more information, see links below.
Cancer Care, Inc.
Cancer Institute: Cancer-Related Fatigue
10: Cancer-Related Fatigue, Harcourt International Fatigue E-Book
Interactive Textbook on Clinical Symptom Research
Chapter 9 - Fatigue (NIH Pain Consortium)
States Dept. of Agriculture Center for Nutrition Policy and Promotion
Online Medical/Pharmacological Dictionaries
Medical Dictionary, 30th Edition
The Virtual Medical Center
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