Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Cold, Flu, & Cough Health Center

Font Size

Flu Complications - Topic Overview

Although most cases of influenza (flu) get better without causing other problems, complications sometimes develop.

Possible complications of flu include:

Recommended Related to Cold & Flu

Tips for Treating the Cold and Flu

Before cold and flu season gets into full swing, arm yourself against germs. To stave off the flu, start here: "Get a flu shot. That's the single most important thing you can do," says Aaron Glatt, MD, president and chief executive officer of St. Joseph Hospital in Bethpage, N.Y. If a cold or flu does catch you, make sure your medicine chest is stocked with everything you need to relieve your most miserable symptoms. WebMD's experts have the goods on the must-have cold and flu remedies this sea...

Read the Tips for Treating the Cold and Flu article > >

  • Pneumonia, which is an inflammation of the lungs.
    • Primary influenza viral pneumonia develops soon (24 to 36 hours) after flu symptoms start and does not get better with antibiotics. It rarely causes death in young, healthy people, but it can often be life-threatening in older adults, people who have other diseases, and pregnant women.
    • Secondary bacterial pneumonia most often develops after a period of improvement following the flu. People with this type of pneumonia usually get better with antibiotics.
  • Bronchiolitis, which is an inflammation of the small air passages (bronchioles). Bronchiolitis affects infants and is the leading cause of serious lower respiratory illness.
  • Sinusitis, which is an infection or inflammation of the mucous membranes that line the inside of the nose and facial sinuses. Facial sinuses are hollow spaces, or cavities, located around the eyes, cheeks, and nose.
  • Croup, which is a swelling or obstruction in the windpipe (trachea). It causes a distinctive hoarseness and a barking cough, a high-pitched sound (stridor) heard when breathing in, and trouble breathing.
  • Chronic obstructive pulmonary disease (COPD) getting worse.
  • Reye syndrome, which is a very rare but serious disease that most often occurs in children 6 to 12 years old. The exact cause is not known. But it is associated with children who have recently had chickenpox (varicella) or flu (influenza) and have taken aspirin. The disease primarily targets the brain and liver and can cause drowsiness, confusion, seizures, coma, and in severe cases, death.
  • Inflammation of the heart muscle (myocarditis), inflammation of muscles (myositis), or inflammation of the sac around the heart (pericarditis).
  • Fatigue and a lack of energy that persist after flu symptoms are gone. People may take several weeks to fully recover, although no cause for the symptoms has been identified.

    WebMD Medical Reference from Healthwise

    Last Updated: September 09, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    Next Article:

    Today on WebMD

    hot toddy
    15 tips to help you feel better.
    man sneezing into elbow
    Do echinacea and vitamin C really help a cold?
    teen girl coughing
    Get a good night’s rest with these remedies.
    elder berry
    Eat these to fight colds, flu, and more.
    Natural Cold Flu Remedies Slideshow
    cold weather
    Allergy And Sinus Symptom Evaluator
    Boy holding ear
    woman receiving vaccine shot
    woman with fever
    Waking up from sleep
    woman with sore throat