Is It a Cold or the Flu?

Doctor William C Lloyd Healthgrades Medical Reviewer
Medically Reviewed By William C. Lloyd III, MD, FACS
Written By Amy Rushlow on June 17, 2021
  • Man with Cold
    Which Bug Is It?
    There’s no cure for the common cold or seasonal influenza. Both are caused by viruses, so antibiotics won’t help. Bad news when you’re sniffly, achy, and overall miserable. More than 200 viruses cause a cold, but fewer cause the flu. Which bug is bearing down on you?
  • Fever Might Mean Flu
    Fever Might Mean Flu
    Burning up? You probably have the flu if you have a fever—at least 100 degrees—that lasts three to four days. Fevers are rare in people with colds and are usually milder. Call your doctor if you have a fever higher than 102 degrees, or if your fever lasts a long time.
  • Notice Your Nose
    Notice Your Nose
    If your symptoms are primarily in the nose, it’s a cold. A schnoz running like a faucet is a telltale sign. (Check the color of your mucus. Yellow or green? That’s a cold.) A stuffy or runny nose can happen with the flu, too—it’s just rarer. If a runny nose doesn’t get better within 10 to 14 days, see your doctor. You might have a bacterial sinus infection called sinusitis, which should promptly respond to a course of antibiotics.
  • Signs May Develop Slowly or Quickly
    That Aching Back
    Do you feel like you were just hit by a bus? Body aches are a sign of influenza, especially severe aches and pains in your back, arms, and legs. Take an over-the-counter pain reliever and get plenty of rest.
  • Close up of woman's hand holding thermometer
    Pay Attention to Timeline
    The flu is fast and furious. Influenza hits you suddenly, with chills, a fever, and body aches. If your sickness worsened bit by bit, it’s probably a cold. With either illness, call your doctor if you're feeling better and then suddenly get much worse, with nausea, vomiting, high fever, shaking, or chills. These could be signs of a more serious problem.
  • Chicken Soup Broth
    Forgoing Food?
    Loss of appetite is a sign of the flu. Drink lots of fluids and clear soups if you have either illness. This will loosen mucus and prevent dehydration.
  • A Sleepy Sign, child sleeping, sick, child, cold, flu, fever
    A Sleepy Sign
    Nodding off more than your cat? Fatigue and exhaustion signal the flu. Exhaustion will usually be worse at the beginning of the illness, but fatigue can last for weeks. Cold symptoms usually go away after a week at most.
  • Treating That Cough
    Treating That Cough
    A cough plays on both teams. But a dry cough is usually a sign of the flu. If you have both a cough and a stuffy or runny nose, sustained-release pseudoephedrine (Sudafed®) can help. Avoid the new nonsedating antihistamines, which don’t help a cough. If you’re coughing up mucus, choose an expectorant instead of a cough suppressant.
  • doctor examining male patient's glands
    For Flu, See Your Doctor, Stat
    Pretty sure you have the flu? Get thee to a doctor! Your doctor can prescribe antiviral medicine that will make your symptoms better and shorten the amount of time you’re sick. You’ll need to take the medicine within 48 hours of when symptoms appear for it to work well.
  • Take a Sick Day
    Take a Sick Day
    Here’s your free pass to play hooky. Stay away from work to avoid passing your germs on to coworkers. You’re contagious for up to five days after flu symptoms appear. A cold is most contagious in the first two to three days. Plus, rest helps your immune system fight the viruses.
Cold or Flu: Which Is It?

About The Author

  1. Colds and the Flu. American Academy of Family Physicians.
  2. Colds and the Flu: Tips for Feeling Better. American Academy of Family Physicians.
  3. Stopping the Spread of Germs at Home, Work and School. Centers for Disease Control and Prevention.
  4. Common Cold. U.S. National Library of Medicine, National Institutes of Health.
  5. Flu (Influenza): Treatment. National Institute of Allergy and Infectious Diseases, National Institutes of Health.
  6. Cough and the Common Cold: ACCP Evidence-Based Clinical Practice Guidelines. M.R. Pratter. Chest. 2006, no. 129, 72S-4S.
  7. Influenza Symptoms. Centers for Disease Control and Prevention. Is It a Cold or the Flu? National Institute of Allergy and Infectious Diseases, National Institutes of Health.

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Last Review Date: 2021 Jun 17
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.