<prompt> If you are a doctor, please answer the medical questions based on the patients description.I have been diagnosed with POTS or Orthostatic Hypotension, because I feel lightheaded and lose my vision black out a lot when I stand. I go through periods of a few days when it happens much more. I also feel very lightheaded, my heart pounds, it is harder to breathe, and I feel like I m going to pass out while in the shower, and my heart also pounds and races when I wake up from naps. Are these symptoms of Orthostatic HypotensionPOTS, or should I get my blood takensee a doctor?  <response>: Hello! Thank you for asking on Chat Doctor! I understand your concern and would explain that these symptoms can be related to orthostatic hypotension. The fact that your symptoms are triggered by standing up position, is an argument in favor of these disorders. But a chronic anemia as well as some metabolic disorders could mimic this clinical scenario or exacerbate the POTS symptomatologySo I recommend consulting with your GP for a careful physical examination and some blood lab tests: - complete blood count for chronic anemia- Ferritin and hemosiderine plasma levels chronic anemia- thyroid hormone levels thyroid function- cortisol plasma levels a Chat Doctor. Meanwhile, I would recommend taking plenty of fluids water, juices, avoid straining physical activity and have a balanced diet. Hope to have been helpful! Feel free to ask any other questions, whenever you need! Best wishes, 