Introduction

If you catch flu, you don't just catch a cold. You'll probably feel very ill with a headache, fever, chills, body aches, and a cough.

Some people need hospital treatment. But most people recover without it.

We've brought together the best research about flu and weighed up the evidence about how to treat it. You can use our information to talk to your doctor and decide which treatments are best for you.

Flu is an infection of your airways. It's caused by the flu virus. Flu is normally worse than a cold, and it can make you feel very ill.

Flu stands for influenza. There are three types of influenza virus: A, B, and C. Types A and B can make you very ill. ^[1] Type A is the world's most common flu virus. ^[2] It usually makes you more ill than type B. ^[3] Type C isn't normally very serious.

Doctors diagnose flu by looking at your symptoms. They only test for a particular virus if they are monitoring a type of flu that could spread to lots of people.

The flu virus lives in your nose, your throat, and the air passages leading to your lungs. You usually get a fever, body aches, chills, and a dry cough. The flu virus can also cause more serious problems, such as pneumonia. ^[1]

When you're infected with a virus, your immune system tries to fight it. If you've recovered from a virus before, your body will know how to deal with it in the future. This means that you won't get ill if you come into contact with the same virus again. But the influenza virus changes all the time. ^[1] This is called mutation. So you can catch the flu even if you've had it the year before.

Flu spreads very easily from person to person. You can get it from people who cough, sneeze, or talk near you. ^[3] You can get the flu from someone while they are ill or a few days before they have any symptoms.

Some people in Asia, Russia, and Turkey have caught a more serious type of flu from close contact with birds. It's called bird flu or avian flu. To read more, see Bird flu.

During 2009, a new type of flu, commonly referred to as swine flu, spread around the world. See our information on Swine flu to find out more.

Flu vaccines help to prevent some types of flu. To read more, see Flu vaccines.

Glossary

immune system

Your immune system is made up of the parts of your body that fight infection. When bacteria or viruses get into your body, it's your immune system that kills them. Antibodies and white blood cells are part of your immune system. They travel in your blood and attack bacteria, viruses and other things that could damage your body.

pneumonia

Pneumonia is an infection in your lungs. Anything that causes infections (bacteria, viruses or fungi, for example) can give you pneumonia.

For more terms related to Flu

Citations