Cold and Flu Symptoms, and How Signs of the Flu Differ From Those of a Cold
Infectious DiseasesCold & Flu

Symptoms of Flu and the Common Cold

Symptoms of Flu and the Common Cold
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Updated on January 20, 2026
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Your nose is running, you’re coughing, and you feel tired and achy. Do you have the flu or just a cold?

Both the flu and common cold are caused by contagious respiratory viruses, and they share many symptoms. But there are differences that can help you figure out why you’re sick, so that you can know what to expect and seek out the right treatment.

This is especially important if you have the flu, which is more likely than the common cold to lead to potentially serious complications, like bronchitis and pneumonia.

Flu Symptoms in Adults

Flu symptoms usually come on suddenly and tend to be more severe than symptoms of the common cold. You may feel like you were hit by a truck and struggle to get out of bed.

Symptoms typically include:

  • Fever or feeling feverish/chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Fatigue
  • Muscle or body aches
  • Headaches
  • Vomiting and diarrhea (more common in children)

Occasionally adults with the flu have no fever, at least not at first. Some go on to develop a fever, some do not. “Children tolerate high fevers better than adults, but 102 degrees F is a significant fever, especially for adults,” says Randy Bergen, MD, a pediatric infectious disease consultant in Walnut Creek, California.

Illustrative graphic titled How Flu Affects the Body shows fever, runny nose, sore throat, vomiting, fatigue, body aches, cough and headache. Everyday Health logo
The flu can cause any or all of these symptoms.Everyday Health

How Long Do Flu Symptoms Last?

Flu symptoms usually last for two or three days, but certain symptoms can linger:

  • Fever may persist for five days.
  • You may cough and feel weak and fatigued for weeks.
  • Your airways may be irritated or you might feel wheezy for up to two months.

Signs of a Flu Emergency in Adults

The following warning signs should prompt immediate medical care for adults with flu, including:

  • Difficulty breathing or shortness of breath
  • Persistent pain or pressure in the chest or abdomen
  • Persistent confusion, dizziness, inability to arouse
  • Seizures
  • Not urinating
  • Severe muscle pain
  • Severe weakness or unsteadiness
  • Fever or cough that improves, then returns or worsens
  • Worsening of chronic medical conditions

Flu Symptoms in Babies and Children

Flu symptoms in children are similar to those in adults, but children are more likely to experience vomiting and diarrhea.

Babies who have the flu seem especially sick, fussy, uncomfortable, and unhappy, compared with babies who just have a cold.

Signs of a Flu Emergency in Babies and Children

Babies and children under age 5 are especially at risk for serious flu-related complications. Children with chronic health problems, such as asthma, have the highest risk of complications.

Symptoms in babies or young children that should prompt immediate medical attention include:

  • Fast breathing or trouble breathing
  • Bluish lips or face
  • Ribs pulling in with each breath
  • Chest pain
  • Severe muscle pain (child refuses to walk)
  • Dehydration (no urine for eight hours, dry mouth, no tears when crying)
  • Not alert or interactive when awake
  • Seizures
  • Fever over 104 degrees F not controlled by fever-reducing medication
  • Any fever in children younger than 12 weeks
  • Fever or cough that improves, then returns or worsens
  • Worsening of chronic medical conditions

Symptoms of the Common Cold

Cold symptoms typically appear about one to three days after exposure to a cold-causing virus.

Symptoms of a cold may include:

  • Runny or stuffy nose
  • Sore or scratchy throat
  • Cough
  • Sneezing
  • Generally feeling unwell
  • Slight body aches or a mild headache
  • Low-grade fever

When nasal symptoms start, you may have an excess of clear mucus that gradually thickens and may change color to yellow or green — this is usually normal and not a sign of a bacterial infection.

How Long Do Cold Symptoms Last?

The full life cycle of a cold is usually between 4 and 10 days, although some people may have a cough that lasts into the second week.

When to Seek Medical Care for Cold Symptoms and Complications

Most people recover from colds without incident, but complications requiring medical care (such as sinus or ear infections or acute bronchitis) are possible.

For Adults Seek medical care for the following:

  • Unusually severe cold symptoms
  • High fever or a fever lasting longer than four days
  • Dehydration
  • Difficulty breathing
  • Symptoms that don’t improve after 10 days
  • A cough that worsens even as other symptoms improve
  • Flare-up of a chronic medical condition such as asthma
For Children Get medical care immediately if a child experiences any of the following:

  • Fever of 100.4 degrees F in newborns up to 12 weeks
  • Rising fever or fever lasting more than two days
  • More-intense symptoms, such as headache, throat pain, or cough
  • Difficulty breathing or wheezing
  • Ear pain
  • Unusual fussiness or drowsiness
  • Lack of interest in eating

The Takeaway

  • Flu symptoms can overlap with those of the common cold; both can cause runny nose, coughing, sore throat, and headache, among other shared issues.
  • Flu symptoms tend to come on more suddenly than those of the common cold, and can be more severe.
  • Flu fatigue tends to be greater than feeling tired because of a cold; with flu you may even struggle to get out of bed.
  • Whether resulting from the flu or a cold, certain complications such as difficulty breathing should mobilize you to seek emergency medical care.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Influenza (Flu). Merck Manual. October 2025.
  2. Signs and Symptoms of Flu. Centers for Disease Control and Prevention. August 26, 2024.
  3. Influenza (Flu) and Your Baby. March of Dimes. July 2024.
  4. Common Cold. Mayo Clinic. May 24, 2023.
  5. Common Cold. Merck Manual. October 2025.
  6. Facts About the Common Cold. American Lung Association. October 30, 2024.
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Michelle Seguin, MD

Medical Reviewer
Member of American College of Lifestyle Medicine

Michelle Seguin, MD, is a board-certified family medicine, lifestyle medicine, and certified functional medicine physician (IFMCP). She is a practicing physician at Root Functional Medicine, a leading telemedicine practice specializing in personalized, root-cause care.

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Erinn Connor

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Before joining Everyday Health, Erinn worked for The Bergen Record in northern New Jersey writing features about food, health, fashion, pop culture and everything in between. Before that she interned at the Dallas Morning News in Texas, the Columbus Dispatch in Ohio, and the Green Bay Press-Gazette in Wisconsin covering everything from Super Bowl XLV to strawberry farming to the journey of a young man who became blind in his 20s. She graduated from Syracuse University in 2010 with bachelor’s degrees in magazine journalism and anthropology.

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