Fatigue
Not just being tired. Fatigue is one of the most common complaints, yet one of the most complex to solve. It can stem from mitochondrial dysfunction, thyroid issues, anemia, chronic infections, sleep disorders, nutrient deficiencies, or HPA axis dysfunction. The key is finding YOUR underlying cause.
Major Causes of Fatigue
Mitochondrial Dysfunction
ATP production impaired. CoQ10, B vitamins, carnitine deficiencies. Toxin exposure.
Thyroid Issues
Hypothyroidism slows everything. Check TSH, free T3, free T4, antibodies. Common miss.
Anemia
Iron, B12, folate deficiency. Less oxygen delivery. Check ferritin, not just hemoglobin.
Sleep Disorders
Sleep apnea, insomnia, poor sleep quality. Non-restorative sleep. Often overlooked.
Adrenal/HPA Dysfunction
Chronic stress → cortisol dysregulation. "Adrenal fatigue" pattern. AM fatigue, PM wired.
Chronic Infections
EBV reactivation, Lyme, other stealth infections. Immune system constantly fighting.
Fatigue Investigation
Basic Labs to Check
- CBC: Anemia, infection signs
- Iron panel + ferritin: Ferritin below 50 can cause fatigue
- Full thyroid: TSH, free T3, free T4, TPO antibodies
- B12, folate: Both cause fatigue when low
- Vitamin D: Under 30 = common fatigue cause
- Blood sugar: Fasting glucose, HbA1c
Deeper Investigation
- Cortisol: AM cortisol, 4-point saliva, or DUTCH
- EBV panel: Check for reactivation
- Sleep study: Rule out apnea
- Organic acids: Mitochondrial function markers
- Hormones: Testosterone, estrogen, progesterone
- Inflammatory markers: CRP, ESR
Chronic Fatigue Syndrome (ME/CFS)
Key Features
Profound fatigue lasting 6+ months. Post-exertional malaise (PEM). Unrefreshing sleep. Cognitive dysfunction.
Possible Mechanisms
Mitochondrial dysfunction, autoimmunity, viral persistence, autonomic dysfunction, neuroinflammation.
Triggers
Often follows viral infection (EBV, COVID). Also trauma, surgery, severe stress.
Management
Pacing is critical. Avoid PEM triggers. Address underlying infections, mito support, nervous system work.