One common cause of obstructive sleep apnea is enlarged tonsils or adenoids (tissues located in the passage that connects the nose and throat). Treatment can help teens with sleep apnea, so any who have symptoms (such as loud snoring or excessive daytime sleepiness) should be checked by a doctor. Reflux Gastroesophageal reflux disease (GERD) is another common cause of sleep loss. But frequent nightmares can disrupt sleep patterns by waking someone during the night. If nightmares are interfering with your teen`s sleep, consider having him or her talk to a doctor, therapist, or other counselor. Doctors usually treat narcolepsy with medicines and lifestyle changes. Sleepwalking, which may run in families, tends to happen most often when a person is sick, has a fever, is not getting enough sleep, or is feeling stress.