The NHS explains: "Addison's disease is usually the result of a problem with the immune system, which causes it to attack the outer layer of the adrenal gland (the adrenal cortex), disrupting the production of the steroid hormones aldosterone and cortisol.
Addison's disease, also called primary adrenal insufficiency or hypoadrenalism, is a rare disorder affecting the adrenal glands.
The rare disorder the NHS says could be mistaken for the flu The NHS is cautioning that during this time of year, it might be easy to confuse flu symptoms with those of a rare condition.
This condition arises when the outer layer of the adrenal glands (the adrenal cortex) is damaged, leading to reduced hormone production.
The adrenal glands, located on top of the kidneys, are small but vital organs that produce two essential hormones: cortisol and aldosterone.
