Types of cold viruses
More than 200 types of viruses can cause a cold. Those most responsible belong to one of two groups:
Because a number of viruses can cause a cold, it's possible to have several colds, one after the other, because a different virus causes each one.
The viruses that cause a cold affect the lining of the nose and throat causing symptoms such as sore throat, runny nose and sneezing.
Types of flu viruses
Flu (influenza) is caused by types A, B or rarely C influenza virus. Only types A and B cause major outbreaks and severe disease, while type C can cause an illness in children similar to the common cold.
Most people are infected with influenza A virus. This virus has caused flu pandemics (worldwide spread of a new disease) and most epidemics (widespread occurrence of an infectious disease in a community at a particular time).
You can catch flu all year round, but it is especially common in winter. When this happens it is called 'seasonal flu'. Influenza A viruses are found in many animal species although water birds are its natural host. Types of influenza A viruses you may have heard of include Avian (Bird) flu and H1N1 (Swine) flu. Influenza B virus is primarily a human disease.
Ways to help prevent flu can include:
- annual flu vaccination
- antiviral medicines, although these are only recommended for preventing flu if you have been exposed to the flu in the previous 48 hours
Not sure what to do next?
If you are still concerned about your cold or flu, why not use healthdirect's online Symptom Checker to get advice on when to seek medical attention.
The Symptom Checker guides you to the next appropriate healthcare steps, whether it's self care, talking to a health professional, going to a hospital or calling triple zero (000).
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Last reviewed: May 2018