A history of recent (within several months)
corticosteroid therapy is a strong indicator for
adrenal insufficiency. The diagnostic path includes
tests to measure the levels of potassium, sodium,
GLUCOSE, cortisol, and ACTH in the blood. Other
procedures typically include ACTH- and CRH-
stimulation tests to assess the body’s ability to pro-
duce cortisol. The endocrinologist may conduct
diagnostic imaging procedures such asMAGNETIC
RESONANCE IMAGING(MRI) or COMPUTED TOMOGRAPHY
(CT) SCANto visualize and evaluate the pituitary
gland and adrenal glands.
DISTINGUISHING FEATURES OF ADRENAL
INSUFFICIENCY AND ADDISON’S DISEASEAdrenal Insufficiency Addison’s Disease
low ACTH normal ACTH
normal SKINcolor areas of hyperpigmentation
normal BLOODpotassium elevated blood potassium
level level (HYPERKALEMIA)
normal blood sodium level low blood sodium level
(HYPONATREMIA)
normal blood GLUCOSElevel low blood glucose level
(HYPOGLYCEMIA)
normal ALDOSTERONE deficient aldosterone
production production
Treatment Options and Outlook
Treatment consists of medication (hormone ther-
apy), typically oral hydrocortisone, to supplement
adrenal production of cortisol until the pituitary
gland returns to normal ACTH production. Most
adrenal insufficiency resolves within a year of
onset. When the cause of the adrenal insufficiency
is permanent, such as damage to or destruction of
the anterior lobe of the pituitary gland, permanent
hormone therapy becomes necessary as well. Dur-
ing treatment it is important for the person to
remain vigilant for signs of adrenal crisis, which
requires emergency medical treatment. Circum-
stances that increase the risk for adrenal crisis
include physiologic stress such as trauma, INFEC-
TION, surgery, and PREGNANCYand CHILDBIRTH.
Risk Factors and Preventive MeasuresThe leading risk factor for adrenal insufficiency is
corticosteroid therapy. The typical approach is to
taper the corticosteroid DOSEgradually, to allow
the body’s normal hormonal mechanisms to
resume. Abruptly stopping a corticosteroid med-
ication after taking it for four weeks or longer
greatly increases the risk for adrenal insufficiency.
See also CHRONIC FATIGUE SYNDROME; POLYGLANDU-
LAR DEFICIENCY SYNDROME; STRESS AND STRESS MANAGE-
MENT.adrenocorticotropic hormone (ACTH) A pep-
tide HORMONE, also called corticotropin, the ante-
rior lobe of the PITUITARY GLAND produces to
stimulate the adrenal cortex of the ADRENAL GLANDS
to synthesize and release CORTISOL. ACTH is one of
the hormones in the STRESS RESPONSE HORMONAL
CASCADE. The HYPOTHALAMUSreleases the hormone
CORTICOTROPIN-RELEASING HORMONE(CRH) to stimu-
late the pituitary’s synthesis of ACTH. When corti-
sol levels reach the appropriate level in the
bloodstream the hypothalamus shuts down its
release of CRH and the pituitary gland subse-
quently ceases ACTH production until cortisol lev-
els again drop. This cycle is ongoing as cortisol has
numerous actions within the body, notably to
facilitate carbohydrate and fat METABOLISM and
suppress INFLAMMATIONand other aspects of the
IMMUNE RESPONSE.
For further discussion of ACTH within the con-
text of the endocrine system’s structure and func-
tion please see the overview section “The
Endocrine System.”
See also ALDOSTERONE; FOLLICLE-STIMULATING HOR-
MONE(FSH); GROWTH HORMONE(GH); LUTEINIZING HOR-
MONE(LH); PROLACTIN; THYROID-STIMULATING HORMONE
(TSH).aging, endocrine changes that occur with The
endocrine system initiates many of the significant
changes that mark the phases of life, from CONCEP-
TIONto old age. Because critical endocrine processes
slow with advancing age, many people believe the
endocrine system holds the secrets to aging and
thus the answers to slowing or preventing the
changes that occur in the body that cause aging.
The most obvious endocrine changes that occur
with age are those that regulate sexual maturation
and reproduction. The onset of PUBERTYheralds the
transition from childhood to adulthood and nearly
every ENDOCRINE GLANDplays a role. The HYPOTHAL-
AMUS steps up production and secretion of
GONADOTROPIN-RELEASING HORMONE (GNRH), GROWTH110 The Endocrine System