What it is
Daytime fatigue or sleepiness involves excessive drowsiness during waking hours, potentially indicating sleep apnoea, hypersomnia, anaemia, hypothyroidism, or depression.
Research-supported
Daytime fatigue or sleepiness
Excessive drowsiness, low energy, or persistent urge to sleep during normal waking hours, which may indicate disrupted sleep or an underlying health condition.
CategoryFatigue
Reviewed by Internal Medical Editorial Team · Editorial Health Review
26 March 2026
At a glance
Daytime fatigue or sleepiness at a glance
Commonly experienced as
- Daytime fatigue and sleepiness create a pervasive impairment that most people try to manage through caffeine, increased activity, or simply powering through — all of which reduce sleep pressure overnight and perpetuate the problem. The impact on cognitive function, mood, and motivation is significant. The frustration of sleeping an apparently adequate number of hours yet feeling persistently unrefreshed is common in sleep-disordered presentations.
