Flu Symptoms Last for About a Week

Main symptoms of all types of influenza (seasonal flu, swine flu – 2009 pandemic influenza H1N1, and bird flu – avian influenza H5N1), like fever, severe tiredness, runny nose and sore throat, usually last for 5-10 days. 

  • The first symptom, fever, usually lasts for 1-2 days, sometimes up to 5 days (1). Note: Fever may be absent.
  • Severe tiredness may be present in the first 3-4 days.
  • When fever starts to drop, sore throat, dry cough, runny nose and headache appear or worsen and may last until 5th to 10th day of the disease.

If above symptoms do not cease in 7-10 days, you should visit your doctor to get an exact diagnosis and to check if eventual complications, like sinusitis or pneumonia have developed.

Other relatively mild symptoms, like dry cough and fatigue, may last for up to 2 weeks or more.

You can go back to school or work 24 hours after you no longer have fever after your last dose of a fewer-lowering drug (2).

Duration of flu depends on:

  • Strength (virulence) of viruses that attack you. Viruses in one epidemic can be strong, in an other one week. Even viruses within one epidemic can vary in strength.
  • Age. In general, in children symptoms of flu tend to be worse and last longer than in adults. 
  • Your overall health. In people with low immunity, malnutrition, in chronic patients or alcoholics, symptoms tend to last longer, and complications are more likely.  
  • Treatment. Anti-flu medications can shorten the duration of flu for a day or so and may prevent complications (2), like pneumonia. Fever-lowering drugs, like Tylenol or Advil, usually shorten the duration of fever.

Other infections with flu-like symptoms lasting for about a week:

  • Common cold
  • Croup
  • Viral pharyngitis
  • Viral laryngitis
  • Strep throat
  • Stomach flu – gastrointestinal infection caused by Rotavirus
  • Measles, chicken pox and other childhood infections with rash
  • Bacterial pneumonia (if treated)

Symptoms lasting for more than two weeks speak either for complications of flu (sinusitis, pneumonia, myositis, pericarditis, myocarditis, meningitis, encephalitis, and so on) or for infections, caused by other microbes, like:

  • Infectious mononucleosis, caused by Epstein-Barr virus (EBV)
  • Acute viral or bacterial sinusitis
  • Whooping cough
  • Viral pneumonia
  • Atypical pneumonia
  • Tuberculosis
  • Lyme disease, caused by bacterium Borrelia burgdorferi
  • Q fever
  • Psittacosis

You can check a list of respiratory infections with causes, ways of spread, symptoms and their duration.

Related Articles:

References:

  1. Fever in flu may last for up to 5 days  (nlm.nih.gov/medlineplus)
  2. Anti-flu drugs can shorten duration of flu for a day  (mass.gov)