What is Chronic Fatigue?

Office worker with chronic fatigue trying to cure their tiredness with a cup of coffee.

Fatigue is a persistent feeling of tiredness, low energy, or exhaustion that does not improve with rest. It can affect physical, mental, and emotional functioning and may be linked to medical conditions, lifestyle factors, or both. Ongoing or unexplained fatigue may be a sign that further evaluation is needed.

Quick Facts

  • Condition type: Symptom / clinical concern
  • Common age group: All ages
  • Treatable: Often manageable once underlying causes are identified
  • Emergency: Rarely; urgent evaluation may be needed if fatigue is sudden, severe, or accompanied by other concerning symptoms

Symptoms of Chronic Fatigue

Fatigue can present in different ways and may include:

  • Persistent or overwhelming tiredness
  • Difficulty concentrating or “brain fog”
  • Low motivation or reduced mental clarity
  • Non-restorative sleep or frequent sleep disturbances
  • Muscle weakness or slowed physical movements
  • Reduced stamina during normal daily activities

What Causes Chronic Fatigue?

Fatigue can have many potential causes, and more than one factor may be involved. Common contributors include:

  • Sleep-related issues: Poor sleep quality, insomnia, or sleep apnea
  • Hormonal or metabolic conditions: Thyroid disorders, diabetes, or blood sugar imbalances
  • Mental health factors: Depression, anxiety, or chronic stress
  • Infections or post-viral conditions: Mononucleosis, long COVID, or other chronic infections
  • Nutrient deficiencies: Iron, vitamin D, or vitamin B12 deficiency
  • Autoimmune or inflammatory conditions
  • Lifestyle factors: Overwork, inadequate nutrition, dehydration, or prolonged stress

Because fatigue is a nonspecific symptom, identifying the underlying cause often requires a medical evaluation

Symptoms of Chronic Fatigue

  • Poor sleep habits or sleep disorders
  • Chronic stress or burnout
  • Nutritional deficiencies (iron, vitamin D, vitamin B12)
  • Chronic medical conditions (diabetes, autoimmune disease)
  • Hormonal changes or endocrine disorders
  • Sedentary lifestyle
  • Recent illness or prolonged recovery
  • Certain medications

Treatments For Chronic Fatigue

Treatment for fatigue depends on identifying and addressing the underlying cause. Management may include:

  • Medical evaluation to assess for contributing conditions such as anemia, thyroid disorders, sleep disorders, or metabolic issues
  • Laboratory testing, including blood counts, thyroid levels, vitamin levels, and blood sugar when appropriate
  • Sleep optimization, including treatment of sleep apnea or insomnia if present
  • Lifestyle adjustments, such as stress management, balanced nutrition, hydration, and regular physical activity
  • Targeted treatment for identified conditions (for example, treating nutrient deficiencies or managing chronic disease)
  • Specialty referral when fatigue is linked to endocrine, sleep, or mental health conditions

Fatigue often improves once contributing factors are identified and appropriately managed.

Specialties That Treat This Condition

What To Do Next?

If symptoms persist or interfere with daily life, a healthcare provider can help evaluate the cause and discuss appropriate next steps.
Medical Disclaimer: This content is provided for general educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment. Conditions and treatment options vary by individual. Always consult a qualified healthcare provider regarding symptoms or medical concerns.