Signs and Symptoms of Influenza: An Overview
It's easy to confuse a
common cold with the symptoms of
influenza (also known as
the flu).
Cold symptoms are usually milder and don't last as long as influenza symptoms. If you become infected with the
influenza virus, you will usually feel symptoms 1 to 4 days later. It is important to note that you can spread the disease to others before your influenza symptoms appear and for another 3 to 4 days after they appear.
These common influenza symptoms start quickly and can include:
- Fever
- Chills
- Dry cough
- Sore throat
- Runny or stuffy nose
- Headache
- Muscle aches
- Extreme fatigue.
Typically, the fever will begin to decline on the second or third day of the illness.
What About the "Stomach Flu?"
Although nausea, vomiting, and
diarrhea can accompany influenza symptoms, especially in children, gastrointestinal symptoms rarely occur. The illness that people call "
stomach flu" is not influenza.
Complications related to symptoms of influenza in adults can occur if they develop a bacterial infection, which can cause pneumonia in already weakened lungs. However, the
flu virus alone can also cause pneumonia. Complications due to influenza usually appear after you start to feel better. After a brief period of improvement, you may suddenly get symptoms, such as:
- High fever
- Shaking chills
- Chest pain with each breath
- Coughing that produces thick, yellow-green mucus.
Pneumonia can be a serious and sometimes life-threatening condition. If you have any of these symptoms, you should contact your healthcare provider immediately to get the appropriate treatment.