At the end of summer when that first nip is in the air, it marks the start of cold and flu season. During our lifetime we experience an average of 200 colds – that’s 5 years of coughs, congestion, headaches and sore throats. 7a Children could have 3-8 cold infections a year, and adults 2-4 colds annually. 8a These are caused by viral infection of the upper respiratory tract. The common cold is usually harmless although it might not feel that way at the time. The most common cold causing culprits are the rhinovirus family of which there are around 160 different cold causing ‘serotypes’ making it possible to have several colds one after another. Viral DNA changes frequently which makes the job of our immune system quite difficult and explains why we tend to get many throughout our lives. 7a