I've finally got to the bottom of why I have been continually catching chesty coughs, colds, flu and chest infections - Asthma!
The winter of 2004/5 saw me with a very bad viral infection which took many weeks to clear. After this I was noticeably asthmatic. I was prescribed a preventer and a reliever, though I had little understanding of asthma or of the use of these inhalers in controlling it. During the rest of the year I felt ok. I had an irritating cough but then I have had this for years. I put it down to my heavy smoking in my youth.
Thinking back over those years now, I believe that it was not the smoking that gave me this cough but asthma. It would seem that I have been suffering from asthma for decades! Now with proper use of both the preventer and reliever inhalers my cough is finally under control. Hopefully, I can look forward to future years with fewer colds and sneezes.