Fatigue Workup in a Teenager
Begin by quantifying fatigue severity using a 0-10 numeric scale over the past 7 days, and if the score is ≥4, proceed with a focused evaluation targeting treatable conditions rather than extensive laboratory testing. 1, 2
Initial Severity Assessment
- Use a numeric rating scale (0-10) asking: "How would you rate your fatigue on a scale of 0 to 10 over the past 7 days?" 3, 1
- Scores of 0-3 (mild fatigue) require no further workup—only routine rescreening at regular intervals 3, 1
- Scores of 4-10 (moderate to severe) warrant immediate focused evaluation 3, 1, 2
- Scores ≥7 typically indicate marked decrease in physical functioning and require urgent attention 3, 1
Focused History: Key Elements to Assess
Fatigue Characteristics
- Onset, pattern, duration, and changes over time—specifically whether fatigue is new, worsening, or chronic 1
- Associated or alleviating factors, and interference with school attendance and daily activities 1
- Post-exertional malaise (worsening after activity) suggests possible chronic fatigue syndrome 4, 5
Lifestyle and Sleep Assessment
- Sleep quantity and quality: Up to 40% of healthy teens experience sleepiness due to insufficient sleep time 6
- Sleep hygiene behaviors: late-night gaming, TV watching, computer/cell phone use, and social media interfering with sleep 3
- Regular sleep schedule adherence and daytime napping patterns 3
- Screen for sleep apnea if there are upper airway concerns or hormonal changes 3
Physical Activity Patterns
- Sedentary adolescents have significantly higher fatigue scores than active peers 7
- Assess current exercise patterns, frequency, and any recent deconditioning 3
- Note that 10.7% of adolescents are sedentary and present with higher fatigue 7
Psychological and Social Factors
- Screen for depression and anxiety, which are among the most common causes of persistent fatigue (18.5% of cases) 8
- Assess for emotional distress related to school performance and social pressures 3, 1
- Evaluate for excessive psychosocial stress from academic or family demands 8
- Screen for alcohol and substance use 3, 1
Medication and Substance Review
- Complete medication review including over-the-counter, herbal supplements, and vitamins—medication side effects are commonly overlooked 3, 2
- Assess for combinations that may worsen fatigue (narcotics, antidepressants, antiemetics, antihistamines) 3
Associated Symptoms (Red Flags)
- B symptoms: fever, drenching night sweats, unintentional weight loss >10% 9
- Pain (abdominal, musculoskeletal, headaches) 3, 1
- Pulmonary complaints or respiratory symptoms 3
- Sore throat, tender lymph nodes, muscle pain, multi-joint pain 4
Physical Examination: Specific Findings to Evaluate
- Lymph node assessment for cervical or axillary lymphadenopathy 2, 4
- Hepatosplenomegaly evaluation 2
- Thyroid examination for enlargement or nodules 3
- Cardiopulmonary examination 5
- Neurologic examination 5
- Skin examination for rashes or other manifestations 9
Laboratory Workup
Initial Screening Tests (for scores ≥4)
- Complete blood count with differential 2, 9
- Comprehensive metabolic panel 2, 9
- Thyroid-stimulating hormone 2, 9
- Erythrocyte sedimentation rate and C-reactive protein for inflammation 2, 9
Additional Testing Based on Clinical Context
- Nutritional assessment: ferritin, vitamin B12, folate, vitamin D, magnesium, zinc if dietary concerns or malabsorption suspected 3
- Anemia workup if CBC abnormal (though anemia is a rare cause at 4.3% of cases) 8
- Consider screening for infectious causes only if specific risk factors present 9
Avoid Extensive Testing
- Imaging studies (chest X-ray, CT, PET/CT) should only be pursued if red flags are present 2, 9
- Previously undiagnosed serious organic disease accounts for only 0.6% of fatigue cases 8
Management Approach
Treat Identified Contributing Factors
- Address sleep disturbances through cognitive behavioral therapy for insomnia, which is the treatment of choice 3
- Improve sleep hygiene: dark room, regular schedule, avoid caffeine/alcohol/high-sugar foods before bed, limit screen time 3
- Treat depression and anxiety if identified 1, 8
- Manage pain effectively 1
- Restore nutritional deficiencies with appropriate supplementation 3
Physical Activity Intervention
- Initiate a structured physical activity program with stretching and aerobic exercise 2-3 times weekly for 30-60 minutes—this is recommended for all patients regardless of cause 2
- High physical activity in the sport group is associated with low fatigue scores 7
- Begin with low-level activities if significantly deconditioned, gradually increasing over time 3
Education and Counseling
- Educate about typical fatigue patterns and set reasonable expectations 3
- Help develop coping strategies and stress management techniques 3
- Address school-related anxiety about falling behind 3
What NOT to Do
- Do not prescribe psychostimulants or dietary supplements—they lack efficacy for fatigue management 2, 9
- Avoid excessive focus on somatic causes to prevent overdiagnosis 8
Special Consideration: Chronic Fatigue Syndrome (CFS)
- CFS prevalence in adolescents is rare (0.11-1.29%) compared to symptomatic fatigue 4
- Diagnostic criteria require: severe disabling fatigue lasting ≥6 months PLUS at least four of: impaired memory/concentration, sore throat, tender lymph nodes, muscle pain, multi-joint pain, new headaches, unrefreshing sleep, or post-exertional malaise 4
- Cognitive behavioral therapy is effective in 60-70% of adolescents with CFS after 6 months, with sustained effect at 2-3 years 4
- Exercise can be harmful in CFS patients due to post-exertional malaise—these patients need activity pacing, not exercise programs 5
- Prompt diagnosis favors better prognosis 4