Myths vs facts: Cortisol and fatigue

The question of myths vs facts about cortisol and fatigue is not directly addressed in the provided context. Generally, cortisol is a stress hormone; chronic stress can elevate cortisol and contribute to fatigue, sleep disruption, and exhaustion. A common myth is that a single salivary cortisol test can diagnose 'adrenal fatigue' – this is not supported by scientific evidence. The link between isolated cortisol levels and fatigue is weak and multifactorial (sleep, diet, mental health). MyBody-X tests do not routinely measure cortisol; blood or 24h urine collections are more reliable. Caveat: persistent fatigue warrants medical evaluation, not self-diagnosis based on hormone levels alone. Evidence level: unclear due to lack of direct context.