adrenal insufficiency Flashcards
what is adrenal insufficiency?
-where the adrenal glands do not produce enough steroid hormone particularly aldosterone or cortisol
what triggers the kidneys to produce cortisol?
-the hypothalamus produces CRH which triggers the anterior pituitary to produce ACTH which triggers the adrenal glands to produce cortisol
what are the three different types of adrenal insufficiency?
- Primary
- Secondary
- Tertiary
what is primary adrenal insufficiency?
-when there is a problem with the adrenal glands themselves that results in the reduction in the secretion of cortisol and aldosterone
what is the most common cause of primary adrenal insufficiency?
Autoimmune condition called Addison’s
what is secondary adrenal insufficiency?
-when there is loss or damage to the pituitary gland resulting in a reduction in the secretion of ACTH , meaning that the adrenal glands cannot be stimulated to produce cortisol
what is the most common cause of secondary adrenal insufficiency?
loss or damage to the pituitary gland due to:
- surgery
- tumour
- infection
- loss of blood flow
- radiotherapy
what is tertiary adrenal insufficiency?
-when there is a lack of CRH production from the hypothalamus, meaning that the pituitary gland cannot be stimulated to produce ACTH and thus the adrenal glands are unable to be stimulated to produce cortisol
what is the most common cause of tertiary adrenal insuffieciency?
-long term use of oral steroids
what are some signs/ symptoms of adrenal insufficiency?
- fatigue
- nausea
- cramps
- abdominal pain
- reduced libido
- hyperkalaemia
- hyponatraemia
- hyperpigmintation
- hypotension
True/False
Addison’s can cause polydipsia and polyuria?
True
what tests are usually done for patients with suspected adrenal insufficiency?
- short synacthen test (ACTH stimulation test)= diagnostic
- sodium/potassium levels
- early morning cortisol
- ACTH levels
- CT/MRI of adrenals if suspected adrenal pathology
- antibody testing
how would ACTH levels differ in primary and secondary adrenal insufficiency?
primary= high ACTH
secondary=low ACTH
what antibodies are present in Addison’s disease?
adrenal cortex antibodies
21-hydroxylase-antibodies
what is done in a short synacthen test?
- performed in the morning
- test involves giving synacthen (wynthetic ACTH)
- the blood cortisol levels are measured at baseline, 30 mins and 60 mins after administration
- the synthetic ACTH will stimulate healthy adrenal glands to produce cortisol and the cortisol levels should at least double
- a failure for cortisol to rise/ if it is less than double of baseline indicates Addison’s disease (primary adrenal insufficiency)
