Hi
@Alex_B, It sounds like you need to see a medical specialist to ensure the appropriate testing, interpretation of test results and diagnosis.
For example,
underactive thyroid can lead to salt craving, constipation, tiredness (see mayo clinic.com - hypothyroidism and healthfully.com - salt craving. And the thyroid gland influences the operation of other endocrine organs such as the adrenal gland.
And sometimes as you query, will a
repeat test for Addison's disease be worthwhile. Please note however that mayoclinic - Addison's disease does list more than one test for the condition.
Also persons on
some medications can get salt cravings etc - e.g. fluid tablets (see livestrong.com - potassium depletion and salt cravings", some persons with
high blood pressure crave salt (webmed.com People with high Blood Pressure crave Salt) and
sustained stress can cause changes in the body which may trigger salt cravings(see livestrong.com above).
Best Wishes, I hope the above may be useful when you next see your doctor.
Dizziness, collapse are symptoms and signs that need urgent hospital attention according to the mayoclinic.