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.
Hypothyroidism: People with this condition have low levels of thyroid hormones. This affects the part of the brain that controls breathing, as well as the nerves and muscles used to breathe. People with hypothyroidism can also be diagnosed with obesity, which can cause sleep apnea. Acromegaly: People with this condition have high levels of growth hormone.