Flu and Flu Shots

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Introduction

The flu is a respiratory disease that affects the nose, throat, and lungs.  The influenza virus type A, B, or C causes it.  The flu is very contagious.  Symptoms include fever, chills, body aches, cough, and a lack of energy.  The flu usually lasts for a week or two.  Severe cases of the flu may require hospitalization and can be fatal.  The flu may be prevented with a vaccine. 
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Anatomy

The flu can affect your upper respiratory system and lungs.  Your upper respiratory system includes your ears, nose, and throat.  A mucus membrane lines your nose and secretes mucus that filters germs and dust when you breathe.  Your sinuses are behind your nose and in the bones of your head and face.  Sinuses are filled with air and are also lined with a mucus membrane.  Your lungs are part of your lower respiratory tract.
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Causes

The flu is very contagious; meaning it can pass quite easily from one person to another.  The flu develops when the influenza virus comes in contact with the lining inside of the nose.  The influenza virus multiplies in the warm moist environment.  The flu typically begins in the nose and throat and can spread into the lungs.
 
The influenza virus spreads easily from person to person.  When a person sneezes or coughs, mucus drops containing the virus float in the air.  You can catch the flu by breathing in the virus.  The flu is also transmitted by hand to hand contact or by touching a surface that the virus is on and then touching your eyes, nose, or mouth
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Symptoms

The flu usually begins suddenly.  It typically begins with a high fever between 102° to 106 F°.  It can cause severe aching and pain in your joints, muscles, and the area around your eyes.  You may feel weak and lack energy.  Your face may be warm, flushed, or reddish.  Your eyes may be watery.  The flu can cause a headache, sneezing, sore throat, and nasal drainage. 
 
The symptoms of the flu usually begin in the nose and throat first and may eventually spread into the lungs.  You may develop a dry cough, cold symptoms, croup, and bronchiolitis.  The flu can also infect your ears.  Some people experience vomiting and dizziness.
 
The flu can have serious and life threatening complications.  Severe cases of the flu can cause pneumonia.  People in high-risk groups are the most vulnerable for serious complications.  People at high-risk include those older than the age of 65; residents in facilities, such as nursing homes; pregnant women; and infants.  People with certain medical conditions have a high risk for medical complications.  Such medical conditions include HIV or AIDS, diabetes, and chronic heart, lung, or kidney disease.
 
Signs of serious complications from the flu include shortness of breath or difficulty breathing, coughing up blood, turning blue, increased fever, dehydration or the inability to drink fluids, and prolonged symptoms or the return of symptoms after improvement.  You should contact your doctor if you are in a high-risk group and contact the flu or if you show signs of complications from the flu.
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Diagnosis

Your doctor can diagnose the flu based on your symptoms, especially during the flu season.  Your doctor may need to examine you to identify the virus that is causing your symptoms.  To do so, your doctor will obtain cells from the back of your throat by gently wiping it with a long cotton tip swab.  Some doctors use rapid tests that can render results while you wait.
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Treatment

The flu can be treated at home with plenty of rest and by drinking plenty of fluids.  Your doctor can recommend rehydration drinks for you or your child.  You should avoid alcohol and tobacco products.  Symptoms may be treated with over-the-counter medications.  Your doctor may prescribe medications to relieve your symptoms and reduce the severity and length of the flu.

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Prevention

You can prevent the flu with thorough frequent hand washing.  Avoid touching your eyes, nose, or mouth when you are around people that have the flu.  Disinfect shared surfaces, such as telephones, keyboards, counter tops, doorknobs, and facet handles.  Use disposable paper towels instead of shared fabric hand towels.  You can also wear gloves during the winter and when on public transportation.

You can avoid spreading the flu by staying away from people while you are contagious.  Cough or sneeze into a disposable handkerchief.  Wash your hands frequently and especially after coughing and sneezing.

An influenza vaccine can be the best way to prevent the flu.  A flu shot is made of an inactive virus and is protective against influenza type A and B.  A nasal mist vaccine made of a live, weakened virus is delivered through the nose.  It helps the cells in the lining of the nose fight off the influenza virus.  You can not get the flu from the influenza vaccine.

Flu shots are usually given at the beginning of the flu season during the months of October and November.  It is recommended that people in high-risk groups receive flu shots in September.  The vaccine reduces the risk of influenza-related death for people in high-risk groups.

Flu vaccines are about 70-90% effective.  It is recommended that children and pregnant women receive mercury-free vaccines.  You should check with your doctor to see if you or your children are candidates for the flu vaccine.

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Am I at Risk

The flu is highly contagious and spreads easily.  A person is the most contagious from the day before they develop symptoms to seven days afterwards.  The influenza virus floats in the air whenever a person with the flu coughs or sneezes.  You can catch the virus by inhaling it when you breathe.  You can also catch the virus by hand to hand contact with a person that has the flu or by touching a surface with the virus on it and then touching your eyes, nose, or mouth.  Your risk of catching the flu increases with the more people you are exposed to, for instance at work, school, or church.  Your risk increases with the more shared surfaces you touch, such as keyboards, telephones, eating utensils, grocery carts, and public transportation railings.

Flu incidences increase during the winter months.  This may be because of a combination of several factors.  For one, more people gather indoors when the weather is cold or rainy.  The influenza virus can live longer indoors where the humidity is lower.  Additionally, the virus can stay suspended in the air longer indoors.

Influenza type A and B can cause flu epidemics.  Epidemics are widespread outbreaks within a geographical area.  Flu epidemics may cause schools or workplaces to close.  Influenza can also cause pandemics, which are outbreaks over large geographical areas.  Influenza type C is not usually associated with widespread outbreaks. 

Influenza type A has several subtypes.  Influenza type A can mutate and change.  This is why new preventative flu shots are created each year to combat the latest version of the virus.

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Complications

People in high-risk groups are the most vulnerable for serious complications.  People at high-risk include those older than the age of 65, pregnant women, infants, and residents in facilities, such as nursing homes.  People with certain medical conditions have a high risk for medical complications.  Such medical conditions include HIV or AIDS, diabetes, and chronic heart, lung, or kidney disease. Flu shots are recommended for those in high-risk groups.  In some cases, people in high-risk groups receive anti-viral medications during the flu season to assist their immune systems.

The flu can have serious and life threatening complications.  Severe cases of the flu can cause pneumonia.  You should contact your doctor if you are in a high-risk group and contact the flu or if you show signs of complications from the flu.  Signs of serious complications from the flu include shortness of breath or difficulty breathing, coughing up blood, turning blue, increased fever, dehydration or the inability to drink fluids, and prolonged symptoms or the return of symptoms after improvement. 

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Advancements

The present flu vaccinations are not related to the vaccines used in 1976 for the Swine Flu.  The Swine Flu vaccine was discontinued after it was associated with Guillain-Barre Syndrome (GBS), a type of paralysis.  Recent flu vaccines do not carry a risk of GBS in children and only have a slight risk of GBS for adults.

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This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.

The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on February 16, 2022. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.