I have had AF since 1996 and have used Warfarin (Coumadin) for the same amount of time. I live in Queensland Australia and we have an organization called QML control. (Queensland Medical Laboratories.) My GP issues a request to QML and they take over from the GP. So no more GP visits. QML has their own doctors qualified in dealing with warfarin. They check the test results and tell you how much warfarin to take and tells you when to have your next blood test done. (I call the people doing the testing blood suckers.) Ha ha. QML telephones or e-mails or text the result and tells you the next date and how much you are to take until the next test. QML has testing sites throughout Queensland and you can go to these if you are, for example, on holidays in another place. I see posts from people who want to know the answers to questions from their GP and seem not happy with that answer. QML has information telling you that the safe level is between 2 - 3. This is depending on why you are taking Warfarin. I am AF so my safe level is to be between 2-3. Full stop. If I get close to 3 they are instructing me to reduce the number of mg to take until it is back to where they want it to be. For 19 years this has worked well for me. BUT 3-weeks ago I was taken from a motel - while on holiday by ambulance to hospital emergency. They found that my INR was 4.7; I had pneumonia; bleeding right lung and a 5cm blood lump in my right lung. Reason for the high INR???? No one seems to know. I have now been taken off warfarin by way of vit K injection and am waiting to have two thirds of my right lung removed. All being well I will be back on warfarin after the operation - so my cardiologist of 19 years tells me. Will I tinker with warfarin myself to feel better etc. Never! If you want answers to questions contact a blood testing laboratory or visit a cardiologist and get an answer which you can trust. Doctors (GPs) are generalist health people and too busy to bother (really) with INR levels and blood tests and the like. I am sure that what I said goes for the world! Remember the statistics. People on Warfarin survive for an average of 5 years. So do not push your luck by wanting to feel better! You may actually make things worse and your live span shorter. Good luck. Looking forward to your reply. Only sensible posts are answered.