What is Flu?
Influenza—“the flu”—is caused by one of the influenza viruses. The flu is a contagious respiratory illness that infects the nose, throat, and sometimes the lungs. The resulting disease can range from mild to severe.
Do I Have the Flu?
You’re feeling awful. Is it just a cold, or could it be the flu? According to the Centers for Disease Control and Prevention (CDC), here’s how you can tell the difference:
|
Signs & Symptoms
|
Cold |
Flu
|
| How symptoms begin | Gradual onset | Sudden onset |
| Fever | Rare | Usual, lasting 3-4 days |
| Chills | Uncommon | Fairly common |
| Headache | Rare | Common |
| Sneezing, runny nose | Common | Sometimes |
| Cough | Mild to moderate | Common, can be severe |
| Fatigue and weakness | Sometimes | Usual |
| Aches | Slight | Usual, often severe |
| How you feel | Unwell, but able to carry on as normal | Too exhausted and unwell to carry on as normal |
Although the flu is a respiratory illness, children sometimes also experience vomiting and diarrhea. These symptoms are uncommon in adults.
Is the Flu Dangerous?
The flu is more dangerous for some people than for others. Pregnant women, infants and children under 5, and those 65 and older are especially vulnerable. Those with asthma, heart disease, or diabetes are also at greater risk because the flu can worsen these conditions. Flu can also open the door to complications such as pneumonia, ear infections, and sinus infections.
How is the Flu Spread?
Flu is typically spread by tiny droplets that are released when infected people cough or sneeze. These virus-containing droplets can travel as far as 6 feet and land in the mouths or noses of others. Flu viruses can live on airborne droplets for several hours. The typically lower temperatures of fall and winter aid their ability to survive in the air. Less commonly, it is possible to be infected by touching a surface or object that has flu virus on it and then touching one’s own mouth, nose, or eyes. Flu viruses can live on hard surfaces for 24 hours. They only survive on tissues for about 15 minutes. An important but little-known fact is that flu-infected people are contagious 24 hours before they experience their first symptom. After symptoms begin, people are highly contagious for the next 3-4 days and can still infect others on days 5 through 7.
How Can I Protect My Family from Flu?
The most effective way to protect yourself and your family is to make sure everyone gets a flu shot as soon as it becomes available each year. An annual shot is needed for two reasons. First, immunity wears off over time. Second, the formula for the vaccine is different every year because the dominant strains of the virus change from year to year.
Can the Flu Shot Cause the Flu?
The flu shot cannot cause the flu. Flu shots either contain inactivated virus, making the shot incapable of causing illness, or else a “recombinant” vaccine that creates immunity using no virus at all. Remember that after you get the shot, it takes about two weeks to develop the antibodies that protect you from the flu. When someone claims, “The flu shot gave me the flu,” it’s likely that they were exposed to the virus before they got the shot or before their body had time to develop protective antibodies. It’s also possible that the formula for the vaccine did not match the strain of flu that infected the person. Even when this is the case, people are likely to get a milder case of flu than they would have had without the shot.
When is the Best Time to Get a Flu Shot?
It’s smart to get a flu shot as early as possible. This allows those protective antibodies to build up in your body before you encounter the disease in your community. While the flu virus is always present, people usually get the flu in the fall and winter. Flu activity often begins in October and usually peaks between December and February. “Flu season” can sometimes continue into May.
My Baby is too Young to Get a Flu Shot. How Can I Protect Her?
The flu can be serious for infants less than six months old. However, they are too young to receive a flu shot. The best way to protect your baby is to get a flu shot yourself and make sure everyone who provides care for your baby is also immunized. If you give birth during flu season, consider the CDC’s statement that “…studies have shown that flu vaccination of the mother during pregnancy can protect the baby after birth from flu infection for several months.”
What Else Can I do to Protect My Family from the Flu?
Frequent hand washing is one of the best ways to prevent the spread of the flu virus. It’s important to scrub all surfaces of your hands: palms, backs, between fingers, and under your nails. Getting rid of germs takes more than just a quick wash and rinse; you need to scrub for at least 20 seconds. That’s about the time it takes to hum the “Happy Birthday” song twice. To see a demonstration of the right way to kill germs through hand washing, check out the video called “Fight Germs. Wash Your Hands” at CDC.gov/cdctv/
