Flu (Influenza)

Influenza (also called flu) is a viral infection that attacks the nose, throat and lungs. Flu symptoms usually last three to seven days.

The flu is different from a cold and typically causes more severe symptoms and complications than cold viruses. According to the Centers for Disease Control and Prevention (CDC), as much as 8% of the U.S. population gets sick from flu each season

Preventing the Flu

Flu immunizations are the most effective way to prevent the flu. Everyone 6 months & older should receive a yearly flu vaccine. Flu vaccination is especially important for adults 65 years and older, who account for most hospitalizations and deaths from flu. Learn more about flu vaccines.

Flu Symptoms

Influenza usually comes on suddenly and may include these symptoms:

  • Fever (often 101 to 103 degrees F)
  • Body aches
  • Chills and sweats
  • Dry cough
  • Headache
  • Tiredness and weakness (can be extreme)
  • Loss of appetite
  • Sore throat
  • Nasal congestion

Diagnosing Flu

Some of the symptoms of flu and COVID-19 are similar, making it hard to tell the difference between them based on symptoms alone.  

Established Michigan Medicine patients with flu-like symptoms can save themselves a trip to their primary care clinic and receive medical guidance from a Michigan Medicine provider through an E-Visit or a Self-Scheduled Urgent Care Video Visit. Both are available through the MyUofMHealth patient portal.

If your provider needs to know for sure whether you are sick with flu, there are laboratory tests that can be done for both influenza and COVID-19.

Flu Treatment

Most people with the flu have mild illness and do not need medical care or antiviral drugs. If you get sick with flu symptoms, in most cases, you should stay home and avoid contact with other people to keep from infecting them. If you must leave home, for example to get medical care, wear a facemask. Wash your hands often to keep from spreading flu to others.

If, however, you have symptoms of flu and are in a high risk group (including young children, people 65 and older, pregnant women and people with certain medical conditions), or are very sick or worried about your illness, contact your health care provider.

Antiviral medication may be prescribed for people with severe illness or to prevent serious complications for at-risk patients.