I waited until i thought my cold had gone before I started running again, yesterday, but this morning my throat feels like it has a golf ball stuck in it and it is really painful to swallow. I think it might be tonsilitis, so I am gonna have to go on antibiotics :(
Eventually diagnosed as chronic sinusitis and put on anithistamine for a month. Drank 3 litres water a day, did no exercise, drank no alcohol for a month. Seems to have done the trick!