A–Z Glossary

influenza

Influenza, or flu, is a viral illness that often begins suddenly with fever, aches, fatigue, and cough.

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Why symptoms can appear suddenly

Why symptoms can appear suddenly

Sudden onset is not the same as sudden damage When clinicians ask when a symptom started, they are not being overly formal; timing helps narrow the possibilities. A symptom may seem to appear suddenly because the underlying issue was silent until a threshold was crossed. For example, a mild change in hydration, blood glucose, inflammation, […]