The only discomfort is the local anaesthetic injection, which stings for about 5 seconds. After that, you wait in anticipation for them to open the
artery in your
leg, but suddenly you realise that they are already in and doing the work. You feel absolutely nothing. Sometimes they may inject a fair amount of the dye and this can cause a hot sensation in your body. So if you suddenly feel hot for a few seconds, don't panic, it is quite normal.