Excessive sleepiness becomes a problem when one cannot stay awake and alert long enough to complete daily tasks. Some types of excessive sleepiness are worse than others.
Mild: Sleepiness is mild if it occurs during rest when little attention is required for the activity. Examples including reading or watching television.
Moderate: Sleepiness is moderate if it occurs during activities that require more attention. They may be physical or mental. One example is during a group meeting.
Severe: Sleepiness is severe if it occurs during physical activities that require full attention. Examples include talking, eating, or driving.