Salt Craving in Adrenal Insufficiency: Primary vs Secondary

Pathophysiological Basis

Salt craving occurs due to mineralocorticoid deficiency, which causes sodium loss and disruption of electrolyte balance 1

Salt craving is a characteristic symptom of primary adrenal insufficiency due to aldosterone deficiency 2, 1
Patients with primary adrenal insufficiency are advised to eat sodium salt and salty foods without restriction as part of treatment 3
Postural hypotension is an associated finding in primary adrenal insufficiency 1

The presence of salt craving should prompt evaluation for primary adrenal insufficiency 1
Mineralocorticoid replacement is evaluated clinically by asking patients about salt cravings, measuring blood pressure in supine and standing positions, and identifying peripheral edema 1

Patients with primary adrenal insufficiency require both glucocorticoid and mineralocorticoid replacement 4
Most patients with primary adrenal insufficiency should take 50–200 μg fludrocortisone as a single daily dose 5
Allowing unrestricted sodium intake and avoiding salt craving is an important component of substitution therapy 3

Salt craving can be used as a clinical indicator to monitor adequacy of mineralocorticoid replacement in primary adrenal insufficiency 5
Persistent salt craving despite adequate sodium intake may indicate the need for increased fludrocortisone dose 5
Patients should avoid potassium-containing salts which are often marketed as "healthy" 1
Avoid liquorice and grapefruit juice as they potentiate the mineralocorticoid effect of hydrocortisone 5

The American College of Physicians recommends assessing for postural hypotension by measuring blood pressure supine and standing in patients with Addison's disease to evaluate the adequacy of mineralocorticoid replacement 6
The Endocrine Society suggests that plasma renin activity is the most objective measure of mineralocorticoid adequacy, and it should be used to guide optimal dosing of fludrocortisone in patients with Addison's disease 6
Increasing fludrocortisone from the typical 0.1 mg daily to 0.2 mg daily can help resolve salt craving and normalize plasma renin activity in patients with Addison's disease, as recommended by the Journal of Internal Medicine 6