Influenza A; Influenza B

The flu usually begins quickly. The first symptoms are a fever between 102 and 106 °F. (An adult usually has a lower fever than a child.)

Other common symptoms include:

• Body aches
• Chills
• Dizziness
• Flushed face
• Headache
• Lack of energy
• Nausea and vomiting

Between day 2 and day 4 of the illness, the fever and "whole body" symptoms begin to fade.

Then breathing symptoms begin to increase. The symptom is usually not a dry cough. Most people also develop a sore throat and headache. Runny nose and sneezing are common. It is a clear, watery nasal discharge.

These symptoms (except the cough) usually go away in 4 - 7 days. Sometimes, the fever returns. The cough and feeling tired may last for weeks.

Some people may not feel like eating.

The flu can make asthma, breathing problems, and other long-term illnesses worse.

Most people of do not need to see a doctor or nurse when they have flu symptoms. This is because most people are not at risk for a severe case.

People who become very sick with the flu may want to see a health care provider. People who are at high risk for flu complications may also want to see a doctor if they get the flu.

When many people in an area have flu, a doctor can make a diagnosis after hearing the symptoms. No further testing is needed.

There is a test to detect the flu. It is done by swabbing the nose and throat. The results of this test can be available rapidly. Sometimes, this test can help your health care provider decide the best treatment.

Images

Influenza

Nasal spray flu vaccine

Normal lung anatomy

Review Date: 04/26/2011
Reviewed By: A.D.A.M. Editorial: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine (10/5/2010).

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)