Flu season spiked in December 2024, meaning it’s officially behind us. Right? Well, not exactly—at least not this year. While flu cases typically peak once a season and then start to decline, new data from the CDC found that we can expect a second spike in flu cases in the winter of 2025—and it’s starting now.
The first flu surge, according to the CDC’s Weekly US Influenza Surveillance Report, occurred around December 28, when flu-related visits to doctor’s offices, urgent care clinics, and emergency rooms increased by 6.75%. Typically, this would imply that the worst—or at least, most contagious—of flu season is over, since it had clearly peaked.
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However, such was and is not the case: As of the week ending January 25, 2025, ILI (influenza-like illness) visits hit nearly 7%, marking an official second peak—and one even higher than the first. Meanwhile, flu activity is considered “very high” in 29 states, with Southern states Louisiana, Tennessee, and South Carolina being some of the worst hit, and “high” in 15 like Massachusetts, New Hampshire, New Jersey, and New York.
Most of these cases have been caused by Influenza A, with only 2% of cases being Influenza B. The hardest hit group thus far is children under 5 (which parents of young children probably already knew).
Related: How Effective Is the Flu Shot This Year? The Latest Data Shows Surprising Results
“We are seeing another spike in flu after a brief decrease two weeks ago,” Dr. Benjamin Barlow, MD, former senior White House physician and chief medical officer at American Family Care, tells Parade. “According to CDC graphs, we last saw this in the 2017-2018 season. That year was a very bad flu season. The 2017–2018 flu season was one of the longest and most severe in recent history, with 52,000 deaths in the United States, according to the CDC.”
Despite all of this, American adults remain largely under-vaccinated: Only 44% of adults have gotten this year’s flu shot, a far reach from the public health goal of 70%, per the CDC’s report. And that’s too bad because the flu vaccine is very effective—it can reduce the risk of flu-related illnesses by 40% and the risk of hospitalization by 60%, in fact.
“The best way to protect against the flu is getting the season flu vaccine,” says Dr. Zachary Hoy, MD, board-certified pediatric infectious disease specialist at Pediatrix Medical Group. “It has multiple vaccine strains and is based on prediction models of most likely strains, and can prevent getting the flu or decrease the likelihood of severe disease or death from the flu.”
There are plenty of other precautions you can take ahead of the (next) flu spike, too. Ahead, see everything doctors want you to know about influenza, including common symptoms, when to see a doctor, and how to keep yourself from getting or spreading it (possibly for the second time).
What is the Flu Exactly?
“The flu, or the influenza virus, is a contagious respiratory illness and is a fast spreader,” says Dr. Barlow. “The flu is spread mainly by droplets made when someone with flu coughs, sneezes, or talks.”
While we typically say “the flu” when discussing the virus, there are actually various strains of influenza each year. This season, the CDC reports the majority of cases as influenza A and a very small percentage (2%) as type B. “Flu A is the more common of the two strains, but Flu B tends to be more common in children,” Dr. Barlow explains. “Flu A can infect not only humans, but also pigs and animals.” They also both present with similar symptoms.
Related: The One Thing You Should Never, Ever Do Before Getting a Vaccine, According To Infectious Disease Experts
Signs You Have the Flu
Not sure if you have the flu? Keep an eye out for flu symptoms.
“Flu symptoms are similar to the common cold but tend to come on suddenly and are usually more intense than the common cold, Dr. Karla Robinson, MD, licensed, board-certified family physician and medical editor at GoodRx, tells Parade. “You may experience a fever lasting several days, severe body aches, chills, fatigue, chest congestion, cough, and headaches. Sneezing, sore throat, and a runny nose can also occur with the flu.”
TL;DR? Flu symptoms come on rapidly and can include:
- Fever
- Body aches
- Chills
- Fatigue
- Cough
- Chest congesion
- Headaches
- Sore throat
- Runny or stuffy nose
Some people—especially children—may also experience nausea, vomiting, or diarrhea, Dr. Robinson adds.
At-Home Flu Treatment
Usually, it’s wise to treat your flu symptoms by staying home and resting.
“For most people, the flu can be managed at home with simple remedies and over-the-counter (OTC) medications,” says Dr. Robinson. “Getting plenty of rest, staying hydrated, using nasal saline rinses, and taking fever reducers like ibuprofen or acetaminophen can help you feel more comfortable as your body fights off the virus.” Also be sure to stay home to prevent spreading the flu to others, she adds.
If you’re experiencing a sore throat, Dr. Barlow recommends trying lozenges (or cough drops) to provide relief. “Use decongestants and cough medicine to help ease symptoms,” he says.
Related: Here’s What Flu Symptoms Look Like Day by Day
When to See a Doctor
So, when should you consult a medical professional about flu symptoms?
If you’re at high risk for complications
While most flu symptoms can be managed at home, it doesn’t hurt to call your doctor and even set up a telehealth visit when your symptoms start—especially if you are at high risk for complications from the flu, says Dr. Robinson. “This includes adults over 65, people with chronic health conditions such as diabetes, heart disease or lung disease, those with weakened immune systems, and pregnant individuals.”
For a Tamiflu prescription
In some cases, prescription antiviral medications like Tamiflu may be helpful—especially if taken within the first two days of symptoms, Dr. Robinson continues. “These medications may shorten the illness duration by about one or two days and reduce the risk of complications, especially for high-risk individuals,” she says, advising you check with a healthcare professional for a proper diagnosis and to see if you’re a good candidate.
If your symptoms are serious
Regardless of personal risk, however, Dr. Barlow suggests seeking immediate medical attention if you experience difficulty breathing, confusion, shortness of breath, chest pain, ongoing dizziness, gray or blue lips or nail beds, dehydration, or spike a fever over 104 degrees.
“For children, symptoms can sometimes look different and can be harder to spot,” Dr. Robinson says. “Seek emergency care if your child has trouble breathing, bluish lips or face, ribs pulling in with each breath, chest or muscle pain.”
If symptoms initially improve then worsen
Finally, it’s wise to seek medical care if your symptoms initially improve but then worsen, or if they last beyond 7 to 10 days: “In some cases, the flu can turn into bronchitis or pneumonia, which may require additional treatment,” says Dr. Robinson.
Related: 7 Reasons Why Your Throat May Be Sore—and How To Get Relief Fast
How Long Are You Contagious?
“People with the flu are most contagious during the first three days of their illness,” says Dr. Barlow, though it’s technically possible for people to begin spreading the virus before they start showing symptoms. “People remain contagious for up to five to seven days after showing symptoms”
In most cases, symptoms of the virus usually last from three to seven days. That said, Dr. Robinson notes that some people—especially children and those with weakened immune systems—may remain contagious for longer as their bodies may take more time to fight off the virus.
Related: How Late Is Too Late to Get the Flu Shot? Infectious Disease Experts Weigh In
Preparing for Another Flu Spike
“There are typically multiple flu strains circulating each respiratory season, so there can be multiple peaks in one season,” Dr. Hoy reiterates. “The best way to protect against the flu is getting the season flu vaccine.” And no, it’s not too late to get it: “To protect yourself, it’s not too late to get vaccinated if you haven’t already,” says Dr. Robinson.
“Also, practicing good hygiene—washing hands frequently, avoiding close contact with people who are sick, and staying home if you feel unwell—can help reduce your risk of getting sick,” Dr. Robinson concludes.
Up Next:
Related: Feel-Better Foods for Cold and Flu Season
Sources
- “Weekly US Influenza Surveillance Report: Key Updates for Week 4, ending January 25, 2025.” Centers for Disease Control and Prevention.
- Dr. Benjamin Barlow, MD, former senior White House physician and chief medical officer at American Family Care
- Dr. Zachary Hoy, MD, board-certified pediatric infectious disease specialist at Pediatrix Medical Group
- Dr. Karla Robinson, MD, licensed, board-certified family physician and medical editor at GoodRx
