Definition
Fatigue is a complex, multi-factorial experience involving central and peripheral, biological and psychological contributors. It is not simply the opposite of energy.
Why it matters
Persistent fatigue is often misunderstood as weakness, laziness, or depression. It is frequently none of these.
The Science
Fatigue involves central mechanisms (immune signaling, dopaminergic tone, cortical effort systems), peripheral factors (muscle, metabolism), and psychological ones (motivation, catastrophizing). Post-viral, post-exertional, and inflammatory fatigues have distinct patterns.
The NSI Perspective
NSI treats fatigue as legitimate physiology deserving careful evaluation.
Clinical Implications
Systematic evaluation — sleep, thyroid, iron, inflammation, mental health, post-viral considerations — outperforms dismissal.
Practical Application
Persistent fatigue that rest does not fix deserves clinical seriousness.
References
- 1.Chaudhuri A, Behan PO. Fatigue in neurological disorders. Lancet. 2004;363(9413):978–988.