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.
There is no blood test to diagnose sleep apnea. Sleep apnea causes oxygen levels to drop. This puts stress on. the heart and other parts of the body. As a result, people with. sleep apnea are at higher risk for heart disease and stroke. Some studies suggest sleep apnea may also increase the risk. for diabetes and worsen the effect of diabetes on the eyes. and kidneys.