Dangerous Flu Symptoms You Should Never Ignore

Dangerous Flu Symptoms You Should Never Ignore

Dizziness, trouble breathing and other signs you need medical attention.

Most cases of the flu are a nuisance—you’ll be on your back for a few days or weeks, and then you can return to your normal routine. But certain flu symptoms, like sudden dizziness, may signal a more serious medical problem, like sepsis or pneumonia. What’s more, the flu shares many symptoms with COVID-19, which can make it difficult to distinguish between the two.

Make sure you know how to differentiate normal symptoms from serious ones and when to seek help, so you can prevent a potentially life-threatening situation.

Normal flu symptoms
There are some telltale signs of the flu that most people can expect to experience, though not everyone will have all symptoms. These include:

  • Fever/chills
  • Fatigue (tiredness)
  • Muscle or body aches
  • Headache
  • Cough
  • Stuffy nose
  • Some people may have vomiting and diarrhea, though this is more common in children than adults.

Note that these symptoms may also be signs of COVID-19. For that reason, experts advise that anyone older than 6 months of age get the flu shot. Doing so not only protects you from the flu, but it may also help healthcare providers distinguish between flu patients and those with COVID-19 during a season when both respiratory infections are expected to be circulating.

It’s ideal to get your flu shot before the end of October, but even getting it in January or February is better than not at all. It takes about two weeks after getting the vaccine for your body to develop antibodies that protect you from the flu.

Many believe that if you have the flu, it has to come with a fever—but that's not the case. While most people develop a high temperature, not every person with the flu will.

Most of the time, these mild flu symptoms subside after one or two weeks, even without treatment. In some cases, those with weakened immune systems or who are at higher risk of developing complications—like pregnant women, young children, seniors, nursing home residents and people with certain conditions—will need antiviral medications. These prescriptions can minimize symptoms, shorten the time you have the flu by one or two days and prevent major complications.

If you’re in a high-risk group, you should call your doctor at the first sign of the flu. And, if you’re very sick or worried about your symptoms, it’s best to go ahead and see your doctor. Antiviral medications work best if you start them within the first two days of symptom onset.

Serious symptoms that are cause for concern
In addition to the typical signs of flu, there are some age-dependent factors that may indicate a more serious problem. These are some of the potentially dangerous symptoms:


  • Trouble eating
  • Difficulty breathing
  • Crying without tears
  • Fewer wet diapers than usual


  • Breathing problems
  • Bluish skin tone
  • Trouble drinking adequate fluids
  • Difficulty waking up or interacting with others
  • Increased or unusual irritability
  • Improvement in flu symptoms to later return with fever and cough 
  • Fever accompanied by a rash


  • Shortness of breath
  • Abdominal discomfort or chest pain
  • Sudden dizziness
  • Confusion
  • Extreme or persistent vomiting
  • Flu-like symptoms that improve but then return with fever and worse cough

If you or a loved one have any of these symptoms, call 911 or go to the emergency room. They could be a sign of a severe illness, like pneumonia, an asthma attack, sepsis, inflammation of the heart or brain or a severe case of COVID-19. If left untreated, these conditions can be life-threatening. If you think you may have COVID-19, put on a medical grade or double-layer fabric face covering before help arrives.

What to do if you do get the flu
Getting the flu vaccine and practicing healthy habits—like washing your hands regularly, avoiding sick people and eating a healthy diet—can help prevent the disease and keep germs from spreading. But if you do happen to contract the flu, here’s what you should do:

  1. Call your doctor if you have serious symptoms, or if you have an increased risk of flu-related complications.
  2. Stay home (unless, of course, you’re going to the doctor) and try to avoid contact with others.
  3. Get plenty of sleep, and make sure you rest when you need to.
  4. Stay hydrated. Take a look at the color of your urine and how often you’re urinating—it should be clear to light yellow and you should be urinating every three to five hours or so.
  5. Take ibuprofen or acetaminophen if you have muscle aches or a fever.

The flu virus should be taken very seriously, especially for children and the elderly. While most will recover within a couple of weeks, you should keep your doctor in the loop if your symptoms don’t improve.

Medically reviewed in July 2018. Updated in October 2020.

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