• image.alt
  • With Mayo Clinic internist

    James M. Steckelberg, M.D.

    read biography

Mayo Clinic Health Manager

Get free personalized health guidance for you and your family.

Get Started

Free

E-Newsletters

Subscribe to receive the latest updates on health topics. About our newsletters

  • Housecall
  • Alzheimer's caregiving
  • Living with cancer

Question

H1N1 flu (swine flu) symptoms: Is fever always present?

Do H1N1 symptoms always include fever?

Answer

from James M. Steckelberg, M.D.

While most people infected with H1N1 flu (swine flu) develop a fever greater than 100 F (37.8 C), some people don't experience fever with H1N1 infection.

H1N1 symptoms commonly include:

  • Fever
  • Coughing
  • Sore throat
  • Runny or stuffy nose
  • Headaches or body aches
  • Chills
  • Fatigue

H1N1 symptoms may also include vomiting or diarrhea in some cases.

Diagnosing H1N1 flu may be a little trickier in people who don't develop a fever. And it may be more difficult for these people to know when it's safe to go back to work or school. CDC guidelines currently recommend staying home for at least 24 hours after your fever subsides — without the use of fever-reducing medicines.

Next question
H1N1 flu (swine flu) symptoms: Self-care for the flu
References
  1. Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team. Emergence of a novel swine-origin influenza A (H1N1) virus in humans. New England Journal of Medicine. 2009;360:2605.
  2. What to do if you get sick: 2009 H1N1 and seasonal flu. Centers for Disease Control and Prevention. http://www.cdc.gov/h1n1flu/sick.htm. Accessed Nov. 3, 2009.

AN02042

Nov. 6, 2009

© 1998-2010 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

Print Share Reprints

Text Size: smaller largerlarger