Flu Symptoms

Fever generally lasts 3-5 days, and is often higher in the afternoons and evenings, with some decrease in the mornings. Fever typically runs higher in children and can be over 104°.

The cough starts as dry and hacking and progresses by the 3rd day to wet with thick mucous. The cough can worsen for the next 4-7 days and could last for over 2 weeks. This is the major symptom of influenza. Cough in children can be croupy and serious. Smokers are at risk for significant bronchitis and pneumonia.

Headaches and Muscle Aches
These can be severe for the first few days and will slowly improve.

Fatigue is common and severe, lasting for 1-3 weeks.

Sore Throat
Sore throat is most common in older children and adults. It can be severe for the first few days.

Nasal Congestion and Red Eyes
Nasal congestion lasts for 1-2 weeks, and eyes may be red for 3-4 days.

Vomiting or Diarrhea (in children <6 years of age)
Vomiting or diarrhea is unusual in adults. These symptoms are typically seen in children less than 6 years of age and last for the first few days.

Influenza is typically contagious for 5-7 days from fever onset.

Call your physician if:

  • Your instincts tell you to be concerned. Trust them and call your doctor for advice.
  • Your fever comes back after it has been gone 1-2 days or if you still have high fever after 4 or 5 days.
  • Your cough becomes wheezy or rapid, you are having trouble breathing, or you are coughing up bloody or yellow-green mucous.
  • You have any chronic illness (e.g., heart or lung trouble, asthma, cancer, a compromised immune system, diabetes, kidney, or blood cell problems), or if you smoke, and your condition worsens. These conditions put you at greater risk for complications.
  • You have any of the following: severe confusion, seizures/convulsions, loss of consciousness, spasms, bleeding, heart irregularity, ear pain or prolonged headache.