Primary hyperaldosteronism

Question 1

What is primary hyperaldosteronism?

Answer 1

A condition of autonomous aldosterone overproduction from the adrenal glands causing hypertension, hypokalaemia, and suppressed renin

Question 2

What was primary hyperaldosteronism classically thought to be caused by?

Answer 2

An adrenal adenoma (Conn’s syndrome)

Question 3

What is now the most common cause of primary hyperaldosteronism?

Answer 3

Bilateral idiopathic adrenal hyperplasia

Question 4

Why is it important to distinguish between adrenal adenoma and bilateral hyperplasia?

Answer 4

Because adenomas are treated surgically, whereas bilateral hyperplasia is treated medically

Question 5

What proportion of primary hyperaldosteronism cases are caused by bilateral adrenal hyperplasia?

Answer 5

Approximately 60–70%

Question 6

What proportion of cases are due to an adrenal adenoma?

Answer 6

Approximately 20–30%

Question 7

What other less common causes of primary hyperaldosteronism exist?

Answer 7

Unilateral adrenal hyperplasia, familial hyperaldosteronism, and adrenal carcinoma

Question 8

What is the aldosterone level in primary hyperaldosteronism?

Answer 8

Elevated

Question 9

What happens to renin levels in primary hyperaldosteronism and why?

Answer 9

Renin is suppressed due to volume expansion and negative feedback

Question 10

How does aldosterone cause hypertension at the renal level?

Answer 10

By increasing sodium reabsorption via ENaC channels in the collecting duct, leading to water retention

Question 11

How does aldosterone cause hypokalaemia?

Answer 11

By increasing potassium excretion in the distal nephron

Question 12

Why does primary hyperaldosteronism cause metabolic alkalosis?

Answer 12

Increased hydrogen ion excretion in the kidney

Question 13

What are the key biochemical consequences of excess aldosterone?

Answer 13

Sodium retention, hypokalaemia, metabolic alkalosis, and hypertension

Question 14

What is the most common clinical feature of primary hyperaldosteronism?

Answer 14

Hypertension

Question 15

Why is primary hyperaldosteronism considered underdiagnosed?

Answer 15

It often presents as resistant or “essential” hypertension without obvious hypokalaemia

Question 16

How common is hypokalaemia in primary hyperaldosteronism?

Answer 16

Present in only 10–40% of patients

Question 17

In which subtype is hypokalaemia more commonly seen?

Answer 17

Adrenal adenoma (Conn’s syndrome)

Question 18

What symptoms can hypokalaemia cause in primary hyperaldosteronism?

Answer 18

Muscle weakness, fatigue, cramps, and occasionally arrhythmias

Question 19

Which patients should be screened for primary hyperaldosteronism?

Answer 19

Patients with hypertension and hypokalaemia or treatment-resistant hypertension

Question 20

What is the recommended first-line screening test for primary hyperaldosteronism?

Answer 20

Plasma aldosterone-to-renin ratio (ARR)

Question 21

What pattern of results is expected on aldosterone-renin testing?

Answer 21

High aldosterone with suppressed renin

Question 22

Why is the aldosterone-renin ratio elevated in primary hyperaldosteronism?

Answer 22

Aldosterone is autonomously high while renin is suppressed

Question 23

What imaging is used after biochemical confirmation?

Answer 23

High-resolution CT scan of the adrenal glands

Question 24

Why is adrenal vein sampling (AVS) performed?

Answer 24

To distinguish unilateral aldosterone secretion from bilateral hyperplasia

Question 25

When is AVS particularly important?

Answer 25

When CT findings are normal or equivocal

Question 26

How is primary hyperaldosteronism caused by an adrenal adenoma treated?

Answer 26

Laparoscopic adrenalectomy

Question 27

How is bilateral idiopathic adrenal hyperplasia treated?

Answer 27

Aldosterone antagonists such as spironolactone

Question 28

What is the role of spironolactone in treatment?

Answer 28

It blocks aldosterone receptors, reducing sodium retention and potassium loss