Influenza: People with colds often say they have flu, but what's the difference?
Flu, or influenza, is a respiratory infection caused by a virus. The main symptoms are fever, headache and muscle aches and pains. Sore throat, runny nose and cough can also occur.
But you really know it's flu if you feel like you have been hit by a steam roller and just can't get out of bed.
In comparison, a common cold usually only affects the upper respiratory passages, leading to a runny nose, sneezing and a sore throat.
I've heard the flu vaccine can give you flu. Is this true?
The vaccine used to immunise against influenza does not contain a live vaccine and therefore cannot give you the flu. But having said that you can still get the flu even if you have been immunized. This is because the vaccine is only 70 - 90 per cent effective and it can take up to two weeks after immunization before protection kicks in.
Another reason why you may get flu even after successful vaccination is that the flu virus has the ability to change very quickly. This results in the strain used in this year's vaccine not exactly matching the circulating strain.
Having said that, research has shown vaccinated individuals who get flu experience a much milder illness compared to those who have not been vaccinated.
Who should be vaccinated?
There are several groups of people who should be vaccinated annually against flu. These include people; those over the age of 65 years; anyone with a chronic illness; those who's immune systems does not work properly and young people on long-term aspirin therapy.
In addition, residents of nursing homes and other long stay facilities should be vaccinated. It is also recommended that health professionals be vaccinated to protect their own health and that of their patients.
What about complications?
Yes, you can get complications following flu. Most commonly are bronchitis and pneumonia, caused by a secondary bacterial infection. A worsening of a pre-existing condition can also occur. In a minority, flu can prove fatal.
Complications are more likely if the person suffers from ill health, is elderly or is a smoker. Post flu many people complain of feeling depressed and fatigued, but for the majority, flu is a self limiting illness with no long-term effects.