Menu Close


Information about Influenza

We Have to Know about Influenza

  • The flu is a contagious infection of the nose, throat, and lungs caused by the influenza virus.

Causes of Influenza

  • The flu is caused by three types (strains) of viruses — influenza A, B, and C.
  • Flu viruses travel through the air in droplets when someone with the infection coughs, sneezes or talks. One can inhale the droplets directly, or you can pick up the germs from an object, such as a telephone, etc. and then transfer them to your eyes, nose or mouth.

Signs & Symptoms of Influenza

  • Fever – may be high
  • A headache
  • Tiredness
  • A dry cough
  • A sore throat
  • Stuffy, congested nose
  • Muscle aches and stiffness

Risk factors of Influenza

  • Age. Seasonal influenza tends to target young children and older adults.
  • Living or working conditions. People who live or work in facilities along with many other residents, such as nursing homes or military barracks, are more likely to develop influenza.
  • Weakened immune system. Cancer treatments, anti-rejection drugs, corticosteroids, and HIV/AIDS can weaken your immune system. This can make it easier for you to catch influenza and may also increase your risk of developing complications.
  • Chronic illnesses. Chronic conditions, such as asthma, diabetes or heart problems, may increase your risk of influenza complications.
  • Pregnancy. Pregnant women are more likely to develop influenza complications, particularly in the second and third trimesters. Women who are two weeks postpartum are also more likely to develop influenza-related complications.
  • Obesity. People with a BMI of 40 or more have an increased risk of complications from the flu.

Treatment of Influenza


  • Your doctor will conduct a physical exam, look for signs and symptoms of influenza, and possibly order a test that detects influenza viruses.
  • The most commonly used test is called a rapid influenza diagnostics test, which looks for substances (antigens) on a swab sample from the back of the nose or throat. These tests can provide results in 30 minutes or less. However, results vary greatly and are not always accurate. Your doctor may diagnose you with influenza based on symptoms, despite having a negative test result.
  • More-sensitive flu tests are available in some specialized hospitals and labs.

Treatment for Influenza

  • Usually, you’ll need nothing more than bed rest and plenty of fluids to treat the flu. But in some cases, your doctor may prescribe an antiviral medication, such as oseltamivir (Tamiflu) or zanamivir (Relenza). If taken soon after you notice symptoms, these drugs may shorten your illness by a day or so and help prevent serious complications.
  • Oseltamivir is an oral medication. Zanamivir is inhaled through a device similar to an asthma inhaler and shouldn’t be used by anyone with respiratory problems, such as asthma and lung disease.
  • Antiviral medication side effects may include nausea and vomiting. These side effects may be lessened if the drug is taken with food. Oseltamivir has also been associated with delirium and self-harm behaviors in teenagers.
  • Some researchers recommend further study on both of these drugs because of uncertainty about their effects beyond a slight reduction in the time of illness. Some studies have suggested that these medications can also help reduce the severity of complications. The Centers for Disease Control and Prevention still recommends their use for some people.
  • An additional concern is that some strains of influenza have become resistant to oseltamivir, amantadine, and rimantadine (Flumadine), which are older antiviral drug

Self-care of Influenza

  • Rest
  • Take medicines that relieve symptoms and help you rest
  • Drink plenty of liquids
  • Avoid aspirin (especially teens and children)
  • Avoid alcohol and tobacco
  • Avoid antibiotics (unless necessary for another illness)

Investigations of Influenza

  • Lab tests
Symptoms of Influenza
Causes of Influenza