Colorado is in the midst of a record-breaking flu season. In the week ending Dec. 27, 2025, 831 people were hospitalized with influenza – the most since the state started tracking flu cases two decades ago. Hospitalizations eased the following week to 737 but still remain higher than prior years.
Colorado is among the top five states with the most flu activity in the country, with doctor’s visits for flu-like illness at a 30-year record high, according to the Centers for Disease Control and Prevention’s weekly influenza surveillance report.
I’m an emergency medicine and critical care physician at the University of Colorado. In my 18 years of practicing clinical medicine, this year is one of the worst I have seen. Our emergency department hit a record number of single-day total visits over the holidays, and visit volumes have stayed high. Flu is likely contributing to this trend.
While there is always a season where respiratory viruses hit hard, this year influenza is making patients miserable and wreaking havoc on both the state and national health care system.
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How does this year’s ‘super flu’ differ from other flu seasons?
This season is especially rough because of the volume of people seeking emergency care. This flu came on fast and seems to be very contagious, and its symptoms are more severe than other recent years’ flu strains.
Flu tends to cause fever, body aches and maybe a cough. But this so-called super flu has also caused vomiting and diarrhea, which has made people feel much worse than isolated respiratory symptoms alone. When people are feeling worse, they seek emergency care, which is part of why our emergency department is seeing so many people.
In past flu seasons, which typically run from October through February, emergency rooms were full because they were facing multiple outbreaks, such as the 2022 “tripledemic” of COVID-19, flu and RSV.
But this 2025-26 flu season, we’re seeing high emergency department visits specifically from the flu. The first group of patients we’re seeing are healthy people who are feeling worse with this flu, which comes with nausea, vomiting and diarrhea, and come to the emergency department looking for symptomatic relief.
The second group are those with severe manifestations of the flu or who have underlying comorbidities such as asthma or heart disease that can be exacerbated by influenza. This is a population that may require oxygen, or they’re a transplant patient and they’re requiring hospitalization.
This double whammy of people feeling really miserable from their symptoms plus people with comorbidities experiencing complications is when you really see a strain on the health care system.
Are any age groups being hit harder than others?
The U.S. is seeing the highest number of visits to emergency departments in children ages 5 to 17.
Kids seem to be having milder cases than adults, which is typical for some of these viruses. But there have been 17 pediatric deaths from influenza across the U.S., with eight in the week ending January 3. That number of pediatric deaths at this point in the season is not typical.
Young people in their 20s are feeling pretty bad from this year’s flu, but we’re not seeing a lot of complications or hospitalizations in this group across the U.S. and in emergency departments in Colorado.
The main group we’re seeing are people who have a medical problem or underlying conditions, such as asthma, as well as diabetes, obesity, heart disease and those who are immune-compromised. They get the flu, and then it leads to kind of a cascade, or a worsening of their underlying medical problems. This is different from what we saw with COVID-19, where healthy people got very, very sick from COVID-19 itself.
The older you get, the more likely you are to experience complications, such as needing oxygen, which typically requires hospitalization.
Are you still encouraging people to get the flu shot if they haven’t yet?
Yes, you should still consider getting your flu shot, especially if you have medical problems.
Getting an annual, updated flu shot helps with severity of diseases, even if it doesn’t provide total protection. Especially if you have underlying conditions, it’s important to do everything you can to decrease symptom severity, duration and risk of hospitalization.
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When should you consider going to an emergency room?
Anytime breathing becomes difficult, or you experience severe chest pain or headaches that are abnormal, that’s something that we want you to seek medical care for right away. And of course, if somebody’s worried about a symptom, we’re here 365 days a year, and we’re happy to help.
If you are feeling bad – such as a mild headache, body aches, fever, sometimes some cough and congestion, and as I mentioned with this flu, potentially vomiting and diarrhea – that is very normal.
If it’s flu, COVID-19 or RSV in a healthy, mildly symptomatic patient, it doesn’t really matter what they have, because there’s not a specific treatment. There’s not anything that we can do that’s going to make them better, other than “tincture of time,” meaning lots of rest.
If you have underlying medical problems, such as diabetes, lung problems or are immune-compromised, and you are experiencing severe symptoms, you should at the very least see your primary care doctor if not the emergency department.
Is it important to get tested for the sake of knowing what you have?
A lot of patients want to know what virus they have, but if you’re young and healthy, there’s not really a need for testing other than surveillance.
Colorado’s infectious disease trackers say wastewater surveillance is the No. 1 way to figure out what infectious diseases are in the community. We can’t get a comprehensive sample through hospitals and clinics, because there are so many people who are home, don’t get tested and do not seek health care.
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Right now, wastewater samples in Colorado are testing extraordinarily high for the flu and pretty low for RSV and COVID-19. Wastewater is a very reliable test because everybody produces wastewater.
In addition, it’s important for the overall health care system that laboratory testing be used judiciously. Testing does help us understand what’s in the community. But from a hospital and emergency department lens, the more tests we send to the lab that have to be run, the more testing services for other illnesses get backed up. It also adds a burden to nursing and other clinical staff, as well as costs for the patient and hospital.
But if a patient is sick with manageable symptoms from a virus, it’s the same standard advice: Stay at home, wash your hands and consider a mask if you have to go out in public.
