Last flu season was light, but this year has brought with it some "ominous signs," Fauci of the NIH said Tuesday.
Flu cases started going up early, toward the end of November and the beginning of December, he said.
"And it went up on a pretty steep trajectory," he said. "The last time we saw that happen that way was the flu season of 2003 and 2004, which turned out to be a bad flu season."
The type of flu that is going around is called H3N2, which is often linked to more serious disease compared to other flu varieties, Fauci said.
But there's good news: That type of flu matches up well to the vaccine that is being distributed and given out throughout the United States.
People may get more complications from this particular strain of H3N2, "which may make them ill for a longer period of time," Dr. Michael Jhung, medical epidemiologist in the influenza division at CDC, told CNN's Mary Snow.
"But symptoms typically last up to seven days for a normal infection, a noncomplicated infection with influenza," he said. "And we usually see that from year to year regardless of what strains are circulating."
In a "light" year, a few thousand people may still die, but a particularly serious year could see up to 49,000 deaths from the flu, Fauci said. "There's an average of about 200,000 hospitalizations and there's a lot of economic burdens."
If you haven't gotten an annual flu vaccine, it's not too late, doctors say. To further protect yourself, try to avoid anyone who is sneezing and coughing, and wash your hands. Also, exercise and eat healthy foods, Zich said.
Most flu patients should not go to an emergency room, Zich said. They will likely be sent home, as there is very little that can be done for them. A fever as high as 103 degrees Fahrenheit is common in the flu.
Patients with normal flu symptoms should get a lot of rest and take painkillers to help with muscle aches, Zich said. "In five to seven days, you're going to be feeling yourself again," he said.
But there are scenarios in which going to a hospital is necessary. If a patient is short of breath, or can't keep fluids down because of nausea, these are signs of a problem that needs immediate attention, as vomiting or sweating from fever can lead to dehydration, Zich said.
An otherwise healthy person will not get much benefit from antiviral medications designed to treat symptoms that the flu causes, Zich said. The side effects from both oseltamivir (Tamiflu) and zanamivir (Relenza) include nausea.
The CDC recommends that people who have a higher risk of complications from the flu receive antiviral treatment. These include people with chronic illnesses such as pulmonary, cardiovascular and neurological conditions, as well as anyone 65 years and older and children under age 2.
What many people don't know is that the flu vaccine becomes less effective as you get older or develop other medical problems, Zich said. The flu shot relies on the body's antibodies against the flu, so if the immune system is already compromised, it will not work as well.
If you have the flu, how are you treating it? Send photos of your flu survival kits.