Skip to content
My WebMD Sign In, Sign Up

Cold, Flu, & Cough Health Center

Select An Article
Font Size

Types of Flu

Not all flu is created equal: Some types can make you very ill, while other types of flu cause milder symptoms. Read on to learn about the different types of flu.

What Is the Flu?

Flu, or influenza, is a contagious respiratory infection caused by a variety of flu viruses. Symptoms of flu involve muscle aches and soreness, headache, and fever.

How Does a Flu Virus Make Me Sick?

Flu viruses enter the body through the mucus membranes of your nose, eyes, or mouth. Every time you touch your hand to one of these areas, you are possibly infecting yourself with a virus.

This makes it very important to keep your hands germ-free with frequent and thorough hand washing. Encourage family members to do the same to stay well and prevent flu.

What Are the Different Types of Flu?

There are three types of flu viruses: A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high fevers. Type C also causes flu; however, type C flu symptoms are much less severe.

The flu is linked to between 3,000 and 49,000 deaths and 200,000 hospitalizations each year in the United States. The seasonal flu vaccine was created to try to avert these epidemics.

What Is Type A Flu Virus?

Type A flu or influenza A viruses are capable of infecting animals, although it is more common for people to suffer the ailments associated with this type of flu. Wild birds commonly act as the hosts for this flu virus.

Type A flu virus is constantly changing and is generally responsible for the large flu epidemics. The influenza A2 virus (and other variants of influenza) is spread by people who are already infected. The most common flu hot spots are those surfaces that an infected person has touched and rooms where he has been recently, especially areas where he has been sneezing.

What Is Type B Flu Virus?

Unlike type A flu viruses, type B flu is found only in humans. Type B flu may cause a less severe reaction than type A flu virus, but occasionally, type B flu can still be extremely harmful. Influenza type B viruses are not classified by subtype and do not cause pandemics.

How Is Type C Flu Virus Different From the Others?

Influenza C viruses are also found in people. They are, however, milder than either type A or B. People generally do not become very ill from the influenza type C viruses. Type C flu viruses do not cause epidemics.

Do Different Types of Flu Viruses Hit the Population Each Year?

Different strains of the flu virus mutate over time and replace the older strains of the virus. This is why it's important to get a flu shot each year to ensure that your body develops immunity to the most recent strains of the virus.

WebMD Medical Reference

Next Article:

Today on WebMD

neti pot
Slideshow
Chicken soup
Slideshow
 
Natural Cold Flu Remedies Slideshow
Slideshow
Syringes and graph illustration
TOOL
 
Natural Cold Flu Remedies Slideshow
Slideshow
blowing nose
Video
 
Allergy And Sinus Symptom Evaluator
Health Check
Boy holding ear
Article
 
woman receiving vaccine shot
Article
Bacterial or Viral Infection
Video
 
How To Calm Your Cough
Quiz
Sore Throat
Slideshow
 

WebMD Special Sections