Differentiating Adrenal Insufficiency from POTS is tricky. Almost same symptoms. Can you please describe some hints that could help differentiating between them. I haven't been diagnosed yet. But I feel very tired even Im laying down and sometimes I feel the fainting episode when Im sitting or even laying down. There is almost always 25-30 beats difference between laying down and standing and rarely exceed 30. When I feel more relaxed, and happy the difference reduces to 20 beats (80 to 100). Sometimes I feel like Adrenal rush, fear, and increased heart rate when Im sitting. Properanolol helps a lot in such case. Can I conclude from the last description that I dont have Adrenal Insufficiency because adrenaline causes these symptoms? Does Adrenal Insufficiency means also low adrenaline or it is only related to low cortisol? I started to suspect that my symptoms are more related to anxiety.