I have been feeling extremly tired, I get weak after only a little activity, rapid heart beat and feeling faint.  I am a 26 year old female, I have been to see my doctor twice and went for blood tests and went for tests in cardiology. Everything came back nomal. But I still dont feel like myself and am concerned.
Hello and thank you for using Chat Doctor. I carefully read your question and I understand your concern. I will try to give you me my opinion. As you explain, you feel rapid heart beats, feeling tired or fainting. My opinion is that we have to check for possible rhythm issues. If it is a rhythm problem it is important to catch it, as this are random episodes. Sometimes arrhythmia like supra ventricular tachycardia, atrial fibrillation, extra-systolic beats might be the cause of these symptoms. As you mention, you have already done all the examinations, blood samples and this result fine. This is a very good thing. We are sure that there are no problems like anemia. I would like to remember you to check your thyroid hormones because sometimes they might be responsible for rhythm problems. I will also recommend a holder rhythm monitoring for 48 h to increase the possibility to catch anything. Furthermore, I don't know if you had done it before, but you might repeat it for a long time. If the blood analyze, your cardiac echo and the holder monitoring for 48 h result normal than you have nothing to worry about. It might be just a stressed period. Only if we catch an arrhythmia we can know how to ménage it. Hope I was helpful. Best regards.