Hypersomnia. Is a condition of either excessive daytime sleepiness and sleep attacks (not accounted for inadequate of sleep) or prolonged transition to the fully aroused state upon awakening.
In the absence of an organic factor for the occurrence of hypersomnia, this condition is usually associated with mental disorders.
The individual complains of excessive daytime sleepiness or sleep attacks, or of prolonged transition to the fully aroused state upon awakening (Sleep drunkenness), which is not accounted for by an inadequate amount of sleep.
The sleep disturbance occurs nearly everyday for at least 1 month or recurrently for shorter periods of time, and causes either marked distress or interference with personal functioning in daily living.
There are no auxiliary symptoms of Narcolepsy (Cataplexy, sleep paralysis, hypnagogic hallucinations) and no clinical evidence for sleep apnoea (nocturnal breath cessation, typical intermittent snoring sounds etc.).
Narcolepsy Symptoms. Excessive daytime sleepiness – People with the sickness sleep off without any sign at anyplace and whenever
Diminished alertness for the duration of the day
Hard to focus and complete work
Sudden loss of muscle tone called as cataplexy
Sleep paralysis – Experience an inability to move or talk while falling asleep or after waking
Hallucinations -Semi-alert, start envisioning and experience the fantasies as reality
There is no known causative organic factor, such as neurological or other medical condition, psychoactive substance use disorder or a medication.
Neurological condition such as restless leg syndrome.
Can happen in depression.
source