[Adrenal fatigue or hypoadrenia is a term used by alternative medicine providers to suggest that the adrenal glands are exhausted and unable to produce adequate quantities of hormones, primarily cortisol, due to chronic stress or infections]. Wikipedia
Cortisol is the 'waking' hormone. Normal but can be distressing if one is woken suddenly which can cause a feeling of shock and an alteration of blood sugar which can cause nausea. I was woken suddenly anytime from 3.30 a.m.

; deep, prehensile fear.
What are the symptoms of adrenal gland failure?
Signs and symptoms may include:
Extreme fatigue.
Weight loss and decreased appetite.
Darkening of your skin (hyperpigmentation).
Low blood pressure, even fainting.
Salt craving.
Low blood sugar (hypoglycemia).
Nausea, diarrhea or vomiting (gastrointestinal symptoms).
Abdominal pain.
Addison's Disease can be diagnosed by a professional, both in humans and animals. It isn't something that the man in the street can even hazard a guess at. To get a definitive diagnosis can take many months.
From the Addison Disease self-help web-site
Addison's Disease is a
rare endocrine condition where the adrenal glands cease to function, so that your body no longer produces enough of certain essential hormones, known as steroid hormones. The adrenal glands are small triangular shaped glands that sit on top of your kidneys. Their job is to produce the hormones that keep the body functioning properly ...........