<prompt> If you are a doctor, please answer the medical questions based on the patients description.I don t know if its worth seeing a doctor or not. But I always feel like I m never getting enough oxygen and my heart races a lot, even if I m just sitting down or trying to sleep. Sometimes my vision will fade away and then come right back. And I get confused or like a dream state. Tired all the time. I m starting to sleep 12 hours and more, and can still take a nap. Even though I sleep a lot I now have dark circles under my eyes. I have a healthy diet. I never eat fast food. And watch what I take in. But I m slowly losing weight like crazy! I m 5 6 and 107 pounds. Any clue what could be wrong?  <response>: Respected user, HiT hanks for using Chat Doctor.come have evaluated your query thoroughly. This is most likely combination of anxiety, stress ; deficiency of hemoglobin, vitamins, anti oxidants ; alterations in hormonal levels as thyroid or others. Needs thorough clinical evaluations with history, physical examination and series of laboratory tests. Hope this solves your query. Can ask further doubts without any hesitations. Regards. 