How can i tell whether i have adrenal insufficiency?

Many: Aside from symptoms & physcial signs: fatigue, low blood pressure, low blood sugar, nausea/vomiting, abdominal pain, dizziness, adrenal insufficiency is diagnosed through lab works (cortisol, acth, complete metabolic panel).There is a test called acth stimulatory test that can diagnose adrenal insufficiency.This test is more involved than a blood draw but can provide your doc with useful data.

See your doctor: There are blood tests that can diagnose adrenal insufficiency. Many symptoms mimic it, so you can't diagnose it yourself.