FATIGUE

FATIGUE

  1. 1
    Current Diagnosis
    • The clinical evaluation of fatigue begins with a thorough medical and psychosocial history.
    • Consider monitoring for a month before beginning a laboratory evaluation, because it usually does not yield a diagnosis. Initial evaluation should include a complete blood count (CBC), electrolytes, glucose, liver and kidney function tests, thyroid function tests, and urinalysis.
    • Among the many possible causes of fatigue, the most common include depression, environmental stress, anemia, and diabetes. In many cases, a cause is not determined.
  2. 2
    Current Therapy
    • Any underlying cause discovered in the history, examination, or laboratory evaluation should be treated.
    • If depression, anxiety, or environmental stress is suspected, early assessment and treatment is important.
    • Symptom relief includes exercise, regular sleep habits, family discussion about the impact of fatigue, and a symptom and sleep diary.
  3. 3
    Epidemiology

    Fatigue or tiredness is a common complaint in the general population, representing the chief complaint in nearly 10% of patients presenting to a primary care physician and reported as a symptom in 21% of all patient encounters. While acute, prolonged, and chronic fatigue are relatively common, chronic fatigue syndrome is relatively rare.

     

  4. 4
    Risk Factors

    Risk factors for fatigue in adolescence include having depressive symptoms, being highly sedentary, and, conversely, being highly physically active. In adults, risk factors include age over 65 years, presence of one or more chronic medical conditions, and female gender. Precipitating factors include physical stresses such as infectious mononucleosis and psychological stresses such as job- related problems. Perpetuating factors include physical inactivity, emotional disorders, and disturbances of sleep.

     

  5. 5
    Prevention

    Because physical inactivity, psychological stress, and lack of sleep are predisposing and perpetuating factors for fatigue, it is helpful to advise patients about stress reduction, regular exercise, and proper sleep habits.

     

  6. 6
    Clinical Manifestations

    Fatigue is characterized by general malaise, vague physical discomfort, and an inability to perform routine activities. Acute fatigue is short-lived and generally attributable to physical exertion or an acute illness. Prolonged fatigue is defined as self-reported, persistent fatigue lasting 1 month or longer, whereas chronic fatigue is defined as similar symptoms lasting 6 months or more.

     

  7. 7
    Diagnosis

    The clinical evaluation begins with a thorough medical and psychosocial history. It is important to allow the patient to speak uninterrupted for the first minute or two of the interview, because this often provides pertinent clues. The history should include exploration of all medically unexplained symptoms, inquiry into work and life stressor issues, questions regarding alcohol and other substance use, and the current use of prescription, over-the-counter, and alternative therapies. A mental status examination and screening for depression and anxiety should follow. The Beck Depression Inventory or SIG-E- CAPS mnemonic (Sleep, Interest, Guilt, Energy, Concentration, Appetite, Psychomotor retardation, Suicidal) are useful screening tools. The challenge with the diagnostic workup for fatigue is that most laboratory tests do not yield a significant diagnosis. Repeated studies show that only about 15% of patients in primary care settings will have an organic cause for their fatigue (Harrison, Ponka), and laboratory results affect management in as little as 5% of patients (Rosenthal). The following recommendations for the laboratory investigation of fatigue are adapted from guidelines developed by Dutch, Canadian, and Australian general practice groups (Harrison):

    • Consider monitoring for a month after initial presentation, while initiating conservative management.
    • CBC, electrolytes, glucose, liver and kidney function tests, thyroid function tests, urinalysis.
    • Clues from the history and examination may indicate the need for erythrocyte sedimentation rate, monospot, antinuclear antigen testing, or chest radiography.

    Differential Diagnosis

    The common causes of fatigue are represented in the mnemonic DEAD TIRED (Box 1). Depression, environmental factors such as lifestyle, anxiety, and anemia are among the most common causes of fatigue. Diabetes and other endocrine disorders, including thyroid disease, should be considered, as well as an undiscovered tumor. Many infections, especially those of viral origin, cause fatigue, as well as insomnia and sleep disorders such as obstructive sleep apnea.

    Rheumatologic disorders, such as rheumatoid arthritis, systemic lupus erythematosus, and fibromyalgia, are often accompanied by fatigue. Endocarditis, while rare, is a must-not-miss diagnosis, as are other cardiac conditions such as coronary artery disease. Finally, drugs, either prescription or of personal use or abuse, should be considered.

    Box 1
    Common Causes of Fatigue: DEAD TIRED

    Chronic fatigue syndrome is a specific clinical diagnosis characterized by unexplained persistent or relapsing fatigue, not relieved by rest, that substantially limits daily activity. In addition, there must be at least four of the following: memory or concentration impairment, sore throat, tender cervical or axillary lymph nodes, muscle pain, multijoint pain without swelling or tenderness, new headaches, unrefreshing sleep, or postexertional malaise lasting more than 24 hours.

     

  8. 8
    Treatment

    The treatment of fatigue begins with acknowledging the patient’s concern and providing reassurance and information about the natural course and most frequent causes of fatigue. Any underlying cause discovered in the history, examination, or laboratory evaluation should be treated. If depression, anxiety, or environmental stress is suspected, early assessment and treatment is important. In fatigue that remains unexplained, therapy should emphasize symptom relief and include exercise, regular sleep habits, family discussion about the impact of fatigue, and a symptom and sleep diary. These same therapies, along with cognitive behavioral therapy, have been shown to have moderate benefit in chronic fatigue syndrome.

     

  9. 9
    Monitoring

    Ongoing fatigue can be monitored through a three question assessment:

    • Are you experiencing fatigue?
    • If so, how severe has it been, on average, during the past week? (0– 3 is mild fatigue, 4–6 moderate, and 7–10 severe)
    • How does fatigue interfere with your ability to function?
  10. 10
    References

    Beck A., Ward C., Mendelson M., et al. An inventory for measuring depression. Arch Gen Psychiatry. 1961;4:561.

    Gialamas A., Beilby J.J., Pratt N.L., et al. Investigating tiredness in Australian general practice. Aust Fam Physician. 2003;32:663.

    Harrison M. Pathology testing in the tired patient: a rational approach. Aust Fam Physician. 2008;37:908.

    Poluri A., Mores J., Cook D.B., et al. Fatigue in the elderly population. Phys Med Rehabil Clin N Am. 2005;16:91.

    Ponka D., Kirlew M. Top 10 differential diagnoses in family medicine: Fatigue. Can Fam Physician. 2007;53:892.

    Rosenthal T.C., Majeroni B.A., Pretorius R., Malik K. Fatigue: An overview. Am Fam Physician. 2008;78:1173.

    Sharpe M., Wilks D. Fatigue. BMJ. 2002;325:480.

    Viner R.M., Clark C., Taylor S.J., et al. Longitudinal risk factors for persistent fatigue in adolescents. Arch Pediatr Adolesc Med. 2008;162:469.

KNOWLEDGE BASE
About Genomic Medicine UK

Genomic Medicine UK is the home of comprehensive genomic testing in London. Our consultant medical doctors work tirelessly to provide the highest standards of medical laboratory testing for personalised medical treatments, genomic risk assessments for common diseases and genomic risk assessment for cancers at an affordable cost for everybody. We use state-of-the-art modern technologies of next-generation sequencing and DNA chip microarray to provide all of our patients and partner doctors with a reliable, evidence-based, thorough and valuable medical service.

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