This blog was originally published in 2022. It has been updated in February of 2025 and in October of 2025.
When a child has the flu, parents often wonder what to expect and when to worry. Connecticut Children’s Dr. Ian C. Michelow shares six common developments and red flags to watch for — plus tips on managing symptoms and knowing when to call your pediatrician.
1. Expect fever—often high and for a few days.
Many kids will get fever with the flu—and it’s often the first symptom. If your child has the flu and is running a fever, ask your pediatrician when they should be rechecked for any possible secondary infection like pneumonia or an ear or sinus infection. The cough may linger.
Remember, fever is a good thing; it means the body is doing its job and fighting an infection. Fever-reducing medications may help your child feel more comfortable. The exact temperature usually doesn’t matter, but if it is consistently high, there may be a bacterial infection at play, and you should give your pediatrician a call. Fever can lead to dehydration, so it is important to make sure your child drinks enough liquids. Also, know when fever might be an emergency.
>Related: Everything You Need to Know About Fever
2. Expect heavy congestions, runny nose & cough.
Stock up on tissues and saline spray because you can expect a lingering cough, runny nose, and congestion that may last a week or longer.
Since there are no over-the-counter cold medications approved by the FDA for children under 6 years of age, you can help your child feel more comfortable by using a cold mist humidifier at night, saline drops, honey for kids over a year old, and a little TLC.
3. Expect muscle, joint & body aches.
The flu can make larger muscle groups hurt. So don’t be surprised if you hear, “My leg hurts,” or, “My back hurts,” on repeat. It’s all part of the flu experience.
4. Expect loss of appetite & difficulty eating.
This can be frustrating for parents because we want to see our kids eat and get well. They’ll get their appetite back slowly as the infection passes through their body, but patience is key. It’s more important they stay hydrated because dehydration can become a cause for concern.
Keep popsicles, water, applesauce and other hydrating foods on hand; these may be more appealing than a plate of savory food.
5. Expect stomach symptoms: nausea, vomiting & loose stool.
Your child may complain of nausea, vomiting, tummy aches, and loose stool. Don’t worry, unless your child is unable to drink enough fluid or develops severe diarrhea.
>>Related: Tummy Troubles—Nerves, or Something Else?
6. Expect fatigue, weakness & irritability.
Every kid is different. Some kids run around with a high fever and play as if nothing is wrong, while some may want to nap the day away and sleep longer at night. Irritability is also very common, as with any illness.
⚠️ Key considerations & when to get help:
Get the flu shot (to prevent the flu or make symptoms less severe if you do get the flu). This applies to everyone 6 months and older.
Look out for signs of dehydration: pale, sunken eyes, crying without tears, not urinating at least six times a day, drowsy or confused.
Ask your pediatrician if your child is eligible for Tamiflu, an antiviral flu medication for kids that can shorten the symptoms of flu or prevent it if your child was exposed. Know and understand the side effects, and make your decision with your doctor.
Pediatric urgent care is in Farmington, CT.
We’re here when you need us with evening and weekend care.