Flu (Influenza)

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Flu Slideshow: 10 Foods to Eat When You Have the Flu

Quick GuideFlu Pictures Slideshow: 10 Foods to Eat When You Have the Flu

Flu Pictures Slideshow: 10 Foods to Eat When You Have the Flu

When does flu season begin and end?

Flu season officially begins in October of each year and extends to May of the following year. According to the U.S. Centers for Disease Control and Prevention (CDC), people can follow the development of flu across the United States by following CDC's weekly update of the locations where flu is developing in the U.S. (see the flu map).

Flu vs. cold

Compared with most other viral respiratory infections, such as the common cold, influenza (flu) infection usually causes a more severe illness with a mortality rate (death rate) of about 0.1% of people who are infected with the virus. Cold symptoms (for example, sore throat, runny nose, cough, congestion, and slight fever) are similar to flu symptoms, but the flu symptoms are more severe, last longer, and may include vomiting and diarrhea.

The following table is provided by the CDC to help distinguish between a cold and influenza:

Signs and SymptomsInfluenzaCold
Symptom onsetAbruptGradual
FeverUsual; lasts 3-4 daysRare
AchesUsual; often severeSlight
ChillsFairly commonUncommon
Fatigue, weaknessUsualSometimes
SneezingSometimesCommon
Stuffy noseSometimesCommon
Sore throatSometimesCommon
Chest discomfort, coughCommon; can be severeMild to moderate; hacking cough
HeadacheCommonRare
Medically Reviewed by a Doctor on 4/28/2016
VIEW PATIENT COMMENTS
  • Flu (Influenza) - Symptoms

    Please describe your flu symptoms.

    Post View 55 Comments
  • Flu (Influenza) - Side Effects

    Did you experience any side effects with the flu vaccine?

    Post View 30 Comments
  • Flu (Influenza) - Home Remedies

    What home remedies and/or over-the-counter treatments have helped your flu symptoms?

    Post

Health Solutions From Our Sponsors