Flu - What are the symptoms?

Flu symptoms usually come on quickly. They can make you feel very ill.

They include:[1]

Fever (about 38°C to 40°C)
Shivering
A dry cough
Muscle aches
Headache
Sore throat.

Young children and older people may not have all of these symptoms. But they're more likely to become very ill.[2]

Your doctor will probably decide whether you have flu based on your symptoms. Your doctor can find out for certain if you have flu by testing a sample of fluid from your nose or your blood. But most people won't need these tests.[3]

Most people don't need to see a doctor if they have flu. The best thing to do is to stay at home, rest and drink plenty of fluids. Paracetamol can help with aches or fever.

However, you should see a doctor if you:

Are elderly
Are pregnant
Have a medical condition (such as heart failure or asthma)
Have a young child who has flu
Have symptoms lasting more than a few days.

References

Health Protection Agency. Seasonal influenza: flu. Available at http://www.hpa.org.uk/infections/topics_az/influenza (accessed on 15 October 2007).
Nicholson KB, Wood JM, Zambon M. Influenza. Lancet. 2003; 362: 1733-1745.
Centers for Disease Control and Prevention. Lab diagnosis of Influenza. Available at http://www.cdc.gov/flu/professionals/diagnosis/ (accessed on 15 October 2007).

Glossary

heart failure: When the heart loses its ability to push enough blood through the blood vessels, it is called heart failure.
asthma: Asthma is a disease of the lungs. It makes you wheeze, cough and feel short of breath. Asthma attacks are caused by inflammation and narrowing of your airways, which makes it hard for air to pass in and out of your lungs.

This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.