Addisons disease

Question 1

What is addisons disease

Answer 1

Known as primary adrenal insufficency is a chronic condition characterised by inadequate production or cortisol and aldosterone by the adrenal cortex

The insufficency arises due to destructin and dysfunction of the adrenal glands causing affects of metabolism, fluid balance and the stress response.

Question 2

Name the 3 main mechanisms

Answer 2

1. Destruction of the adrenal cortex
2. Hormal deficency
3. Secondary effects on feedback mechanisms

Question 3

Describe the destruction of the adrenal cortex

Answer 3

The adrenal glands fail to produce sufficent hormones due to damage to the adrenal cortex due to:
1. autoimmue adrenalitis: autoantibodies target adrenal tissue causing progressive destruction
2. Infections e.g. HIV, causing adrenal gland damage

Question 4

Describe hormonal deficency

Answer 4

Cortisol
- produced in the zona fascicultata of the adrenal cortex, it is critical for glucose metabolism, stress response and anti-inflammatory

• The defiency leads to impaired glucogenesis and hypoglycaemia, increased sesitivity to stress, loss of vascular tone leading to hypotentison

Aldosterone
- Regulates sodium + potassium and maintains BP
- Deficency causes: Sodium loss and water depletion leading to dehydration and hypotension as well as potassium retention causing hyperkalemia

Question 5

Describe the secondary effects on feedback mechanisms

Answer 5

• The hypothalmic pituitary adrenal axis attempts to compensate by increasing secretion of ACTH from the pituitary gland.
• Persistant high ACTH levels lead to hyperpigmentations due to stimulation of MSH receptors.

Question 6

What is an adrenal crisis

Answer 6

Life-threatening exacerbation of adrenal insufficiency

Due to chronic hormonal deficency

Triggered by infections, trauma, or surgery, missed medication and severe dehydration

Hydrocortisone is given to mimic the effects of cortisol

Question 7

Clinical manifestations of Cortisol deficiency

Answer 7

• Hypoglycaemia: due to impaired glucogenesis
• Fatigue, muscle weaness: disrupted energy metabolisms
• Weight loss: decreased appetite and metabolic dysregulation
• Hypotension: reduced vascular tone]

Question 8

Clinical manfiestations of aldosterone deficency

Answer 8

• Hyperkalaemia
• Hypovolemia and dehydration due to sodium and water loss

Question 9

Clincial manifestations of high ACTH

Answer 9

• hyperpigmentation
• darkening of the skin

Question 10

Clinical manfiestations of impaired stress response

Answer 10

Severe hypotension
Shock
Electrolyte imbalance