Flu and Cold
The runny nose, sore throat or bunged up feeling of a cold is caused by one of many viruses that infect the upper part of the breathing system (upper respiratory tract). Although a cold can make you feel miserable, in most people they are self limiting. This means the body fights off the infection and cure comes without the need for specific medical treatment.
Influenza - or flu - causes similar symptoms to a cold but tends to be a more severe illness. Although it is also self-limiting in most people, flu can be dangerous for people who are frail or have a weakened immune system. Generally, there are two peaks for influenza occurrence in Hong Kong - one in February and the other in July, but this can be influenced by imported cases of flu from other countries.