There are four types of influenza virus.
*Influenza A : Influenza A viruses cause seasonal flu epidemics practically every year in the United States. They can infect humans and animals.Influenza A is the only type that can cause a pandemic, which is a global spread of disease. Bird flu and swine flu pandemics both resulted from influenza A viruses. An influenza A virus has two surface proteins: hemagglutinin and neuraminidase. These help doctors with classification.
* Influenza B : Influenza B viruses can also cause seasonal epidemics that typically only affect humans. There are two lineages of influenza B: Victoria and Yamagata. Influenza B viruses mutate more slowly than influenza A viruses.
* Influenza C : Influenza C viruses cause mild illnesses — they do not appear to cause epidemics.
* Influenza D : Influenza D viruses mainly affect cattle and do not seem to infect humans.
See also :
* [[Fever]]
* [[Immunological Disorders]]
== Symptoms ==
Flu symptoms can range from mild to severe, and they vary from person to person. Common symptoms of the flu include:
*fatigue
*nasal congestion
*a cough
*headaches
*a sore throat
*body aches
*chills
*a fever
*vomiting or diarrhea, which are more common in children
Some people experience severe symptoms, which can include:
*chest pain
*shortness of breath
*severe pain
*severe weakness
*a high fever
*seizures
*severe dizziness
*loss of consciousness
A person who experiences any severe symptom should receive medical attention.
== Home remedies ==
* The Allium family of vegetables, which includes onions, garlic, leeks and scallions, are known to have beneficial effects on the cardiovascular and immune systems, as well as anti-diabetic and anti-cancer effects.
* [[Zong Gan Ling]]
* [[Ma Huang Tang]] contains antipyretic and virus-reducing properties that can address early stages of influenza and upper respiratory tract infection.
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[[Category:Diseases]]
[[Category:infectious disease]]