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- The most common flu symptoms are body aches, chills, cough, fatigue, fever, and headache; less common symptoms of the flu include sore throat, vomiting, and diarrhea.
- The only way to know for sure that you have the flu is to get tested at the doctor’s office with a nasal or throat swab.
- If you think you have the flu and work with high-risk people, like children or the elderly, make sure you take precautions to prevent the spread of infection.
- Visit Insider’s homepage for more stories.
During fall and winter each year there’s a new season of human influenza viruses, which is different than the common cold. The influenza virus infection causes the flu and usually comes on suddenly.
Within hours of symptom onset, people feel “like they got hit by a ton of bricks,” says Emily Landon, an epidemiologist at the University of Chicago Medicine. The human influenza virus is highly contagious and is spread through the respiratory system, nose, and throat.
Most and less common symptoms of the flu
The most common flu symptoms are body aches, chills, cough, fatigue, fever, and headache. Though symptoms can vary slightly from person to person.
“One person may tell you they had the worst chills of their life, and another may say they coughed for four weeks,” Landon says. But if it’s the flu, everyone experiences those hallmark symptoms “whether you’re 2 or 200.”
You may also suffer from these less common symptoms vomiting, diarrhea, stuffy nose, sneezing, sore throat.
Get tested for the flu at the doctor’s office
Landon says that sometimes people think they have the flu, but they’re sick with something else entirely – a fungal infection, bacterial pneumonia, or even a heart attack. And if you’ve got a 24-hour case of vomiting or diarrhea: “That’s not the flu,” she says. “That’s probably norovirus or some other winter virus.” If that’s the case, check out our article on what you can eat to help relieve those symptoms.
The only way to know for sure whether it’s the flu is a nasal or throat swab test at the doctor’s office. Even if you’ve gotten the flu shot, you may still be susceptible to the flu.
And since the flu is highly contagious, it’s important you know whether you’re infected – that way you can take precautions to prevent spreading the virus. Especially if you spend time around high-risk people for the flu, such as new babies or elderly grandparents.
Testing is also helpful for older people with multiple medical problems or people who can’t articulate what’s wrong, such as babies or people with dementia. Because deciphering what’s happening can be challenging. “And that’s what your doctor is for,” Landon adds.
The flu when you’re pregnant
The flu can infect anybody but there are certain populations at higher risk of developing complications from the infection. The group at highest risk often are immune-compromised or have chronic medical conditions and this includes seniors, diabetes, heart disease, hypertension, pregnant women, and children.
Pregnant women are also considered a high-risk flu group, which is why pregnant women should get a flu shot. Flu in the third trimester increases the risk of early labor and makes women more likely to spread the virus to the newborn baby.
“That can be avoided by getting the flu shot, washing your hands, and not being around other people who are sick,” Landon says. And don’t worry about confusing flu symptoms with general pregnancy discomfort.
“Pregnant miserable is one thing. Early on in pregnancy, you may be tired, have nausea, not feel great,” Landon says. “You should not have chills, sweats, or fever.” If you get the flu or fever when you’re pregnant, see your doctor as soon as possible. Physicians can prescribe antiviral medications, which cut down on symptoms, help prevent complications, and take the edge off.
In general, if you suspect you have the flu but are otherwise healthy, stay home. Reschedule plans, and call in sick from work or school. You should start to feel better in one to two weeks.
Related stories about the flu:
- How to prevent the flu, according to doctors
- Yes, the flu is contagious. Here’s when you’re most likely to spread the virus
- You can’t get the flu from the flu shot, but there are side effects
- How long the flu should last and when you should see a doctor
- The flu vaccine is not 100% effective but you should still get it every year
- What you should eat and drink to get over the flu, according to doctors