Travel & Lifestyle: Most Common Early Warning Signs Of The Flu

Influenza is everywhere right now.

According to data from the Centers for Disease Control and Prevention, more than half of the country is reporting high or very high flu activity. Flu cases are also expected to continue climbing, meaning even more people will contract the virus.

“Numbers of emergency department visits, outpatient visits, hospitalizations are all on the increase, and it looks like this is mostly driven by numbers in children,” Dr. Robert Hopkins, the medical director of the National Foundation for Infectious Diseases, said. Younger adults with the flu are next, but Hopkins said he suspects cases among older adults will soon make up a larger share of the data.

The flu can infect anyone and cause serious complications in healthy people and those at high risk. While hand-washing, mask-wearing and vaccination can help to limit contraction of the flu, it’s a hard virus to avoid.

Here are the first symptoms to look for this winter and what to do if you get sick:

“For most people, all ages, the classic symptoms are going to be a pretty abrupt onset of fever, headaches, body aches are really common,” said Dr. Madison Szar, a pediatrician with Bluebird Kids Health.

Chills are common. Respiratory symptoms, such as cough, runny nose and sore throat may also present early.

The flu shows up a little differently in children.

“Often in kids, especially our younger kids, we can typically see more gastrointestinal complaints,” Szar said.

This includes stomach pain, nausea, vomiting or simply not wanting to eat.

When you’re coming down with a cold, it’s common to have a scratchy throat for a few days before the full sickness hits. This isn’t the case with the flu.

“Flu tends to hit very hard and very fast,” Hopkins said. “People will often be able to tell you within the minute or the hour when their symptoms started.”

Not only do flu symptoms come on more swiftly, but they’re generally more severe than cold symptoms, according to Szar.

While many flu symptoms overlap with the signs of other respiratory viruses, you can’t tell which virus you have unless you take a flu or COVID test. But “generally, if it hits, you feel lousy all of a sudden, you can almost call it to the minute, then that, I can say, is pretty predictably influenza,” Hopkins said.

It’s important to contact your doctor when you notice early flu symptoms.

“There are some anti-virals that we can give, but often will work the best within the first 48 hours of symptom onset,” Szar explained. This is especially important for high-risk patients like those with asthma or COPD, Szar added.

Certain symptoms also require medical attention.

“If you have initial fever, and then fever gets better and it is controlled without medicine, and your fever comes back, that’s a warning sign, from my perspective, that you really need to make sure you see a health care professional at that point, because flu can also set you up for secondary bacterial infections like pneumonia,” said Hopkins.

The flu can also cause dehydration. If you’re feeling lightheaded, dizzy or not urinating frequently, you should talk to your doctor, he said.

If you are one of the millions of people who get the flu this winter, stay home.

“You don’t want to share what you have with others in your family or in your community,” Hopkins said. “The flu is severe for many people. Even if you fight it off just fine, your neighbor or colleague may not.”

Prioritize hydration by drinking water, herbal tea, Gatorade, Pedialyte or something similar.

“Being sick will dehydrate your body pretty quickly and make it harder, not only to fight the infection, but it causes you just not to feel good when you’re dehydrated,” Szar said.

Fever reducers and pain relievers may also help, both doctors said. Decongestants and cough medication can aid adults, but for children over the age of 1, Szar tends to recommend giving honey to ease a cough.

“I would be remiss not to mention, if you haven’t already, the flu vaccine is one of the best ways to reduce the severity of illness, even if you do get the flu,” Szar said.

The flu vaccine reduces the risk of hospitalization or severe disease, and also decreases the length of time that you’re sick. While the fall is the best time to get the vaccine, it’s not too late in the season to obtain it.

“Getting vaccinated can reduce your likelihood of having a second flu through the course of the flu season,” Hopkins said.

“Despite comments that have been made by, shall we say, people in positions of power, the flu vaccine remains the most important active measure we can make to reduce the impact of flu on everyone, 6 months of age and older,” he added.

Flu deaths in children during the 2024-2025 season hit a record high, and several states ― such as Massachusetts and Illinois ― are already reporting pediatric flu deaths for this season, in addition to deaths in older adults.

Hopkins also encouraged people to get the flu shot sooner rather than later because it takes about two weeks to develop a protective immune response.

“If you’ve got a family member or a friend or a colleague that’s not been vaccinated, encourage them strongly to get vaccinated as soon as possible. Let’s minimize the impact of what’s already looking like a bad flu season,” Hopkins said.