Flu is still spreading across United States amid a winter wave of seasonal illnesses. In early February, doctor visits for influenza symptoms and flu-related hospitalizations hit a 15-year high. The tough flu season is straining many hospitals, leading to overflowing emergency rooms, long wait times, and limits on patient visitors.
What's more, flu outbreaks among children have forced schools to close in multiple states.
The 2024–2025 flu season — which has sickened over 33 million Americans so far — is in full force. There's more to come before we're beyond the peak, according to experts.
Seasonal flu activity remains elevated and this season is now considered "high severity," the U.S. Centers for Disease Control and Prevention said in its FluView report for the week ending Feb. 15.
Currently, 42 states and the District of Columbia are reporting "very high" or "high" levels of influenza-like illness activity, per the CDC's most recent data. The South, Southeast and Midwest regions are being hit especially hard.
A record number of people are seeking care. Outpatient visits for flu-like illness have not been this high seen since the 2009-2010 flu season, during the swine flu pandemic.
“We are right now in the middle of a nationwide epidemic of seasonal influenza that is filling emergency rooms,” Dr. William Schaffner, professor of infectious diseases at Vanderbilt University School of Medicine, tells TODAY.com.
The flu is a common and highly contagious respiratory illness caused by influenza viruses.
The majority of the cases in the U.S. are being caused by influenza A, primarily the H3N2 and H1N1 strains, according to the CDC. Flu A tends to be more aggressive in adults and hit earlier than flu B, but flu B can surge later in the season.
The tough flu season comes as the country also sees waves of norovirus, COVID-19, and respiratory syncytial virus or RSV — which some have dubbed a "quad-demic." While it's expected to see these four viruses surge in the winter, the surge in respiratory illness is overwhelming some health facilities.
The 2025 flu season
In the U.S., flu activity tends to peak between December and February, per the CDC. However, the 2024-2025 flu season began later than usual.
After a slow start, influenza activity started increasing dramatically in early December, says Schaffner, and after a slight dip around the holidays, has “taken off” since. According to CDC data, flu activity appears to be stabilizing after peaking for a second time in late January.
So far, the CDC estimates there have been at least 33 million illnesses, 430,000 hospitalizations and 19,000 deaths from flu this season. This includes 86 pediatric deaths.
Currently, positive laboratory tests, outpatient and emergency department visits, hospitalizations and flu-related deaths are all high, CDC data show.
As of data posted Feb. 21, emergency department visits for influenza are "very high" nationally, according to the CDC. Flu-related hospitalizations are higher than they have been during any peak week going back to the 2010-2011 flu season.
Wastewater surveillance is also showing very high levels of flu activity across the U.S. According to WastewaterSCAN, which monitors viruses through municipal water systems, influenza A is in the “high” category nationwide as of Jan. 26. Flu B remains lower but positive detections are rising, a spokesperson for WastewaterSCAN tells TODAY.com.
It's unclear how the rest of flu season will pan out, and it's too soon to tell how its severity will compare to past seasons, experts say.
"We're in the midst of influenza and it's bad, but whether it's different than previous years, we won't know that for months," Dr. Jason Newland, the Division Chief of Infectious Diseases at Nationwide Children’s Hospital, tells TODAY.com.
The 2023-2024 flu season was "moderately severe," and caused an estimated 40 million illnesses and 28,000 deaths, per the CDC. "Last year, we had over 200 pediatric deaths from flu, that was a really bad year," says Newland.
Where is flu surging in U.S.?
The following U.S. states reported "very high" influenza-like illness activity during the week ending Feb. 15, according to the latest CDC data:
- Arkansas
- Colorado
- Connecticut
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Nebraska
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- Ohio
- Oregon
- Rhode Island
- South Carolina
- Tennessee
- Virginia
- Washington
- Wisconsin
The District of Columbia and New York City are also reporting very high levels of influenza activity, per CDC data.
Some hospitals feel strained as flu cases rise
Every winter, hospitals fill up around this time of year due to respiratory illnesses, and this year is no exception.
In early February, the weekly flu hospitalization rate reached a record high of 12.8 per 100,000 — this is the highest peak weekly rate observed during all flu seasons since 2010, per CDC data.
Hospital bed occupancy for influenza increased to 5% during the week ending Feb. 8, up from 2.8% the first week of January, per the latest data from the CDC’s National Healthcare Safety Network.
The surge in flu cases, along with other seasonal viruses, is overwhelming some hospitals.
Tennessee is one of several states currently experiencing the highest levels of flu activity in the U.S.
"My hospital is jammed," says Schaffner, who is based in Nashville. "We have people on stretchers, on gurneys in the emergency room waiting to be admitted, and this is true across the country."
California is also being hit hard. San Diego in particular is seeing a steady rise in flu cases and hospitalizations, Dr. Francesca Torriani, an infectious disease specialist at UC San Diego Health, tells TODAY.com. Compared to this time last year, flu-related emergency department visits are nearly double that of last year in San Diego County, she says.
Also in San Diego, Sharp Chula Vista Medical Center deployed a temporary tent outside their emergency department to triage and treat low-risk patients in response to high volumes of patients with flu symptoms. The hospital could treat 15-20 flu patients per day in the tent, which helped open the availability of beds in the ER for other health concerns, Sharp HealthCare told TODAY.com on Jan. 15.
Louisiana is another influenza hot spot. Janz, who works with LCMC hospitals in New Orleans, says the number of patients hospitalized and in the ICU with influenza has jumped by about 30% since December.
“We’re able to deal with that influx pretty well,” says Janz. However, he notes that the surges in flu-like illnesses can quickly strain hospitals already busy with other patients.
In South Carolina, three major hospital systems tightened visitor restrictions due to increased influenza, NBC affiliate WYFF4 reported on Jan. 16. Spartanburg Regional Healthcare System, Prisma Health and Bon Secours St. Francis began restricting children under 16 and anyone with flu symptoms from visiting hospitalized patients as a safety measure.
Flu is also surging in the Midwest, especially in Ohio. Amid a backdrop of increased RSV and COVID-19 activity, “our hospitals get really busy,” says Newland, who works in Columbus. However, according to Newland, this year’s flu season is less of an outlier and more of a return to pre-pandemic numbers.
Although older adults are driving most hospitalizations, flu is hitting people of all ages. Flu cases among children are surging, crowding pediatrician's offices and forcing school closures in multiple states.
As flu activity continues, experts warn that ER wait times and bed availability may be affected. “We’ve got a lot of work left to do for this season, and it still puts all these hospitals at risk,” says Janz.
Influenza symptoms
Flu symptoms can range from mild to severe. Common flu symptoms include:
- Body aches
- Fever
- Chills
- Cough
- Headache
- Fatigue
- Sore throat
- Stuffy nose
"People are going to feel bad for a few days, but it's something that usually people can ride out at home," says Janz.
Some people are at higher risk of developing severe illness or complications due to influenza. According to the CDC, these include but are not limited to:
- Adults ages 65 and older
- Children under age 2
- People with weakened immune systems
- People with underlying chronic health conditions
- Pregnant women
Flu treatment
Most people will recover from flu without treatment, the experts note. Supportive care such as rest, fluids and over-the-counter medication can help manage symptoms.
The CDC recommends staying home for at least 24 hours until after your fever is gone, except to seek medical attention.
Flu can be treated with antiviral drugs, such as Tamiflu, which are especially important for people at higher risk of severe illness, the CDC says. These require a prescription and are most effective when taken within 48 hours after symptoms begin.
If you are in a high-risk group, feel very sick or have any concerns about flu season, contact your doctor. "They can walk you through when to go and when to not to go in," says Newland.
In some cases, going to the emergency room may be necessary.
"If people start having difficulty breathing, or if people start getting confused or having really high fevers, or they're unable to eat or drink for days ... I would recommend people seek health care," says Janz.
How to protect against flu
It’s not too late to get your annual flu shot, NBC News medical correspondent Dr. Natalie Azar told TODAY in a segment aired Tuesday, Feb. 18.
The influenza vaccine can help protect against flu and its complications, which is especially important for high-risk individuals. It's recommended by the CDC for everyone ages 6 months and older.
The flu shots for the 2024-2025 season include three flu viruses: two flu A strains (H1N1 and H3N2) and one influenza B strain. Flu B can surge later in the flu season, so the flu shot can offer continued protection for months, TODAY.com previously reported.
In addition to getting your flu shot, you can protect yourself and others by taking the following steps:
- Wash your hands often.
- Stay home when sick.
- Avoid sick contacts.
- Wear a mask in crowded, indoor spaces.
