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 condition in which people experience pauses in breathing during sleep. As much as 25 percent of men and 10 percent of women in the United States have the condition, Memtsoudis said. Recent studies show people with sleep apnea are at increased risk for complications, particularly lung and breathing problems, after surgery.