How Do I Know It’s the Flu?

Fever. Cough. Fatigue. Is it the flu?

When someone tells you they have the flu, what symptoms come to mind? Aches and pains? Nausea, fever, vomiting? Nearly all the common viral and bacterial illnesses that trouble us on a seasonal basis have symptoms that we identify as “flu-like,” but what does that really mean?

Influenza is a respiratory infection caused by a virus. Even though it’s depressingly common – especially from mid-November through March – influenza, commonly called "the flu," probably gets blamed for more than its fair share of ills. In general, influenza viruses will cause a more severe illness than other infections such as the common cold. Unlike a cold, which usually begins slowly and often runs its course without a fever, flu symptoms typically include a sudden headache with a dry cough, muscle aches, fatigue, chills and a fever (usually 100ºF to 103ºF in adults or even higher in children). Flu sufferers might also experience a sore throat and a runny or stuffy nose.

Nausea, vomiting and diarrhea are not typical symptoms of the flu, but might accompany influenza infection, especially in children. Even though the term "stomach flu" is widely used, most gastrointestinal illnesses are caused by organisms other than influenza viruses. (Often the culprit is found in contaminated food, which by some estimates sickens 76 million Americans every year.)

Preventing the Flu

The simplest and surest way to avoid becoming a victim of the flu is to be vaccinated against it. Preventive methods such as frequent handwashing or avoiding contact with other people are generally helpful in avoiding illness, but are largely ineffective in stopping a flu outbreak. Influenza virus spreads easily and can be transmitted through the air or on surfaces; this means you can acquire the flu just by breathing the same air or touching the same objects as someone who has the flu.

According to the Centers for Disease Control and Prevention (CDC), influenza is associated with more than 100,000 hospitalizations and 20,000 deaths nationwide each year. Flu-related complications are much more likely to develop among the elderly and people with chronic health problems; this is why the CDC’s Advisory Committee on Immunization Practices (ACIP) recommends that certain groups receive influenza vaccinations first. High-risk groups include:

• People 50 years of age or older.
• Adults and children with diabetes or chronic diseases of the heart, lungs, or kidneys.
• People living in long-term care facilities and group homes.
• Health care workers.
• Women who will be more than three months pregnant during the flu season.
• Those with weak immune systems due to situations such as cancer chemotherapy or HIV infection.

Chris Mol, Manager of Occupational Health Services for the Medical College of Wisconsin, ordered an ample supply of flu vaccine in January but so far has received only a partial shipment; he expects to see the remainder in mid-November. Mike Bernaski, a pharmacy purchaser at Froedtert Hospital, says they ordered their flu vaccines at the beginning of March and the medical practices he works with haven’t experienced any problems or delays thus far.

Side Effects

The most common side effect of flu vaccination is soreness at the site of the injection – flu vaccine is typically administered to adults in the arm and to children in the thigh. Some people (especially children who have not previously been exposed to the flu virus) may experience fever, tiredness or sore muscles. These side effects may begin six to 12 hours after vaccination and might last for up to two days. One important caveat: because chicken eggs are used as part of the flu vaccine production process, people who are allergic to egg protein should not receive the vaccine.

Antiviral Medications

If you realize you are coming down with the flu and can visit your health care provider within the first two days of symptoms, there are several prescription medications – amantadine, rimantadine, zanamivir, and oseltamivir – that can lessen the severity and duration of the illness. In certain cases these antiviral medications are also used to prevent the flu, but they are not as effective as the vaccine and some can have unpleasant side effects. People who are unable to receive the flu vaccine, especially those at high risk for complications, should consult their health care provider about these options.

Easing Flu Symptoms

So you took a gamble and ignored your chance to receive a flu vaccine – and you lost. Your head is pounding, your muscles feel like you went ten rounds in the WWF Smackdown, the thermometer reads 101° and you’re too tired to get out of bed. Now what? Most of us already know the answer to this one: stay in bed, drink plenty of fluids, and take advantage of pain relievers like acetaminophen or ibuprofen. (Because of its association with a rare condition called Reye Syndrome, aspirin or aspirin-containing products should never be given children who are recovering from viral illnesses such as flu or chickenpox.)

People who have the flu usually see their symptoms improve in two or three days, although the fatigue and cough can linger for two weeks or more. In most cases recovery is complete, but some victims develop serious medical complications such as pneumonia. If your illness becomes worse or refuses to clear up, or if you have new or severe symptoms, you should see your health care provider. For most of us, it’s a waiting game – though it might feel like an eternity, you should feel considerably better in a few days.