What’s the difference between a common cold and flu?
It’s sometimes hard to tell. Many of the symptoms are the same and both are caused by viruses, not bacteria, which means you can’t treat colds and flu with antibiotics. Cold symptoms are generally milder than those of flu, and they do not tend to lead to any serious health complications, which flu can.
The common cold at a glance
The common cold is a viral infection affecting the upper respiratory system. Causes include rhinoviruses, respiratory syncytial virus (RSV), parainfluenza virus, adenovirus and coronavirus. Symptoms can appear within 10-12 hours of exposure and can include:
- Runny nose
- Sore or irritated throat
- Low-grade fever (mostly in young children)
Flu at a glance
There are three types of flu virus. Type A viruses cause most cases of human flu and some disease in animals. Type B are less common and cause less severe illness. Type C viruses usually only cause mild flu and are rare. Symptoms of flu tend to be more serious than those of the common cold and can include:
- Sudden fever (usually 39°C or above)
- Dry cough
- Achy muscles
- Sore throat
- Extreme tiredness
- Runny or blocked nose
- Nausea, vomiting and diarrhoea (more common in children)
How Long is Flu Contagious?
The incubation period for flu is usually 1-3 days after exposure. If you have picked up a flu infection, you can infect someone the day before your symptoms develop, and sometimes up to five days after your symptoms appear. That means you can pass on the flu to someone else before you know you have it.
Most people make a full recovery from flu, but it can lead to complications
including bronchitis, pneumonia and in rare cases meningitis.