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What symptoms commonly appear at the beginning of influenza?
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influenza
A colored transmission electron micrograph showing influenza viruses (red) at the outer surface of a host cell.
The onset of influenza is typically abrupt, occurring after an incubation period of one to two days.1
Common symptoms that appear at the beginning of the illness include:
- Sudden chills1
- Rapidly rising fever, typically reaching 38–40 °C (101–104 °F)1
- Fatigue1
- Severe muscle aches throughout the body1
- Diffuse headache1
- Irritation or a sense of rawness in the throat1
While respiratory symptoms such as coughing and nasal discharge are common, they often become more prominent as the disease progresses, rather than being the primary indicators at the immediate onset.1