When sleepiness interferes with daily routines and activities, or reduces the ability to function, it is called “problem sleepiness.”

Sleep disorders such as sleep apnea, narcolepsy, restless legs syndrome, and insomnia can cause problem sleepiness.

Certain medical conditions and drugs, including prescription medications, can also disrupt sleep and cause problem sleepiness.

Sleep disorders may be diagnosed and treated through the use of sleep studies, which analyze many factors and functions in an attempt to isolate the cause of the disorder.