Influenza, commonly known as flu, affects your respiratory system and is caused by a virus, which may be one of several different strains. The virus is contagious and causes serious complications for some people, especially those in high-risk categories. Others only experience a mild case that resolves itself quickly.

Symptoms

Many flu symptoms resemble the common cold, but the flu generally leaves you feeling much worse overall. Influenza usually starts suddenly, and its symptoms often include a fever higher than 100 degrees, chills and sweating. You might experience a headache and aching muscles along with fatigue or general weakness. Influenza symptoms can include a dry cough and congestion.

Spreading

When an infected person talks, sneezes or coughs, she releases droplets containing the virus, according to the Centers for Disease Control and Prevention. The virus then ends up in the mouth or nose of someone else, who might develop influenza. The virus might also end up on surfaces, such as toys, doorknobs or countertops. Another person who touches the surface and then rubs her eyes, nose or mouth might introduce the virus into her own body.

Prevention

The CDC recommends getting the flu vaccine every year to prevent influenza. Each year, the flu shot contains three different strains of the virus, based on predictions for the hardest-hitting strains that year. Washing your hands frequently with warm water and soap is a precaution everyone should take. Avoid touching your face, especially your eyes, nose and mouth. A healthy diet, exercise and plenty of rest helps your immune system stay strong to help you fight off the influenza virus.

Treating Influenza

Managing the symptoms is usually the only treatment needed for influenza. Rest gives your immune system a chance to fight off the illness, while drinking lots of liquids keeps your body hydrated. Pain relievers are an option if you experience a headache or body aches. In certain cases, a physician might prescribe an antiviral medication. According to the Mayo Clinic, these drugs might shorten your case of influenza and help avoid further complications.

Complications

Certain populations run the risk of developing serious complications from influenza. Young children, adults over 65, pregnant women and people with certain chronic medical conditions are at higher risk. Influenza could develop into pneumonia, ear infections, sinus infections or bronchitis. A person with a chronic medical condition could experience worsened symptoms of the condition. In some cases, the complications from influenza result in death. If you are in the high-risk category and get the flu, contact a healthcare professional to determine if an antiviral medication is appropriate.