Rate your current fatigue across 9 dimensions, identify the most likely causes, and get targeted solutions — whether your fatigue is sleep-related or not.
Fatigue and sleepiness are often used interchangeably but are clinically distinct states with different causes, implications, and treatments. Sleepiness is the specific drive to fall asleep — a physiological state measured by tools like the Epworth Sleepiness Scale and reflecting insufficient sleep quantity or quality. Fatigue is a broader state of reduced energy, motivation, and capacity for physical and mental effort that does not necessarily involve wanting to sleep.
The clearest indicator that fatigue has a sleep cause: fatigue is accompanied by sleepiness (the urge to actually fall asleep), is worst in the early afternoon, improves significantly after good sleep, and is worse after nights with less sleep. Sleep-related fatigue responds to sleep improvement strategies: more sleep, better sleep quality, treating sleep apnea, improving sleep consistency, and reducing sleep debt.
Fatigue without sleepiness — or fatigue that doesn't improve with adequate sleep — suggests non-sleep causes: anemia (particularly iron deficiency), thyroid dysfunction, depression, chronic stress and burnout, vitamin D deficiency, dehydration, physical deconditioning, diabetes, or in more persistent cases, post-viral fatigue or autoimmune conditions. If fatigue is severe (interfering with work and daily life) and persistent (lasting 4+ weeks) despite adequate sleep and healthy lifestyle, medical evaluation is warranted.