Flu Symptoms

Medically Reviewed by Nayana Ambardekar, MD on December 12, 2021
3 min read

Unlike cold symptoms, signs of the flu tend to come on suddenly. You might have:

Vomiting and diarrhea with flu is more common in children. 

Get medical help right away if you have:

  • Trouble breathing or shortness of breath
  • Pain or pressure in your chest or belly
  • Sudden dizziness
  • Confusion
  • Severe vomiting

These symptoms can mean your illness is severe.

The symptoms of colds and flu can be a lot alike. Here’s how to tell which one is making you sick:

  • Fever. It can last 3 or 4 days with the flu; it’s rare with a cold.
  • Aches. They might be severe with the flu; they’re mild with a cold.
  • Chills. You’re likely to have them with the flu, but they’re rare with a cold.
  • Fatigue. This is common with the flu and happens sometimes with a cold.
  • Sneezing. You’re more likely to have this with a cold than with the flu.
  • Cough and chest discomfort. This is common with both but tends to be severe with the flu.
  • Stuffy nose. This sometimes happens with the flu but is common with a cold.
  • Sore throat. This can be common with the flu but is more likely with a cold.
  • Headache. This is common when you have the flu but rare with a cold.

In most cases, the best things to do when you have the flu are:

  • Rest at home.
  • Drink plenty of fluids.
  • Avoid contact with other people.

Your doctor might give you prescription medications called antiviral drugs if you’re at higher risk of complications, such as if you:

These medicines -- baloxavir marboxil (Xofluza), oseltamivir (Tamiflu), peramivir (Rapivab), and zanamivir (Relenza) -- work best when you take them 48 hours or less after your symptoms start. Antivirals can decrease the severity and duration of illness and may prevent serious complications related to the flu.

People who are otherwise healthy don’t usually have serious problems from the flu.

Flu complications include:


Seasonal flu follows a pattern, starting in the fall and ending in the spring. The first sign is often a sudden rise in the number of school-age children sick at home. This is soon followed by more illness in other groups, including parents.