I have never really understood what atrial fibrillation is. 1) Can people feel it when they have it? 2) What are the symptoms? 3) Can it only be diagnosed by a medical professional with an ECG machine? I have some very brief (less than 5 seconds usually) and occasional episodes of arrhythmia, missing beats or extra beats. I don't know if this is a sign that could suggest I have AF. I don't get chest pain. I do get episodes of fast heart rate (roughly 100 - 125) and my pulse is high in range most of the time. I have a Pulse Oximeter which shows what the pulse is doing in a little trace at the bottom of the display. Could it be used to diagnose AF? What I actually own is this : but the picture of the trace in that picture is nothing like the one I get in real life. What I get is much more like this picture : Does the trace tell people anything about AF? The NHS info on atrial fibrillation is not very good. I have to "check and assess my pulse". What? Checking and assessing your pulse can give you a good indication of whether you have atrial fibrillation, but a full medical investigation will be needed before a diagnosis can be made. My response to this is, "Yes, I have a pulse, which is super". My pulse rate is usually in the 80s or 90s, but can go higher, sometimes for no obvious reason. Is any of this worth following up? I just wish I could decide for myself whether I have a problem. I really don't want to go and see a doctor about it unless I have the condition because I foresee problems like being bullied and being told I must take statins (Not a chance!) or "Take these BP drugs". The last time I took drugs (beta blockers) to lower my heart rate they also lowered my BP to the extent that I was a whisker away from fainting when I stood up, and when I walked up a slight hill to get to my nearest bus stop.