In contrast, Manser says, a person's passive vocabulary consists of the words whose meanings they knowâso that they do not have to look the words up in a dictionaryâbut which they would not necessarily use in ordinary conversation or writing (The Penguin Writer's Manual, 2004).
Sleep Apnea, Night Terrors, and Nightmares. Sleep apnea may also be to blame for your nightmares. During sleep apnea, your brain senses the low oxygen and realizes that you are under a very real threatâyou are being choked or smothered by your own bodyâand if nothing is done you will die.
Sleep apnea is a breathing condition that's linked to being overweight. Sleep apnea can cause a person to snore heavily and to briefly stop breathing during sleep. Sleep apnea may cause daytime sleepiness and make heart disease and stroke more likely. Weight loss often improves sleep apnea.