The most typical symptoms of hypersomnia are: 
Excessive daytime sleepiness leading to prolonged naps that are not refreshing.

Nocturnal sleep of long duration (as much as 12 hr or more)

Sleep drunkenness

Difficulty in awakening the patients from sleep

Episodes of automatic behavior may also be present.
a. Idiopathic Hypersomnia (Primary Hypersomnia)
Idiopathic hypersomnia is characterized by long periods involving episodes of excessive daytime sleepiness. Most of the time the symptoms are present.

Some people with this disorder experience
automatic behavior such as:
- Headaches
- Dizziness
- Cold hands and feet
- Depression symptoms
b. Post - traumatic Hypersomnia:

Post - traumatic hypersomnia may mimic idiopathic hypersomnia.