(1) Insomniacs may envy those who have no problem sleeping. (2) However, too much sleep is also a sleep disorder. (3) There are a couple of major causes of sleeping too much. (4) One major cause of this problem is apnea, a condition associated with breathing difficulties during the night. (5) In severe cases, the victim actually stops breathing after falling asleep. (6) When the level of carbon dioxide in the blood rises to a certain point, apnea sufferers are spurred to a state of arousal just short of waking consciousness. (7) Because this can happen hundreds of times in a night, apnea patients typically feel exhausted and fall asleep repeatedly the next day. (8) Another cause of too much sleep is narcolepsy, a hereditary condition that causes victims to nod off without warning in the middle of a conversation or other alert activity. (9) Narcoleptics will often experience a sudden loss of muscle tone upon expression of any sort of emotion. (10) A joke, angèr, sexual stimulation-all bring on a feeling of weakness. (11) Another symptom of the disorder is immediate entry into REM sleep, a state which produces frightening hallucinations that are in fact dreams that the narcoleptic experiences while still partly awake. In general, the major supporting details of the passage are _--. causes of apnea. symptoms of narcolepsy. causes of getting too much sleep types of insomniacs. causes of getting too much sleep.