The flu (influenza) is usually identified by a range of symptoms that typically come on suddenly. Common flu symptoms include:
- Fever or feeling feverish, often between 38°C and 40°C or higher
- Muscle and joint pain all over the body
- Headaches
- Sore throat
- Chills
- Extreme fatigue or tiredness
- Dry cough without phlegm
- Blocked or runny nose
- Loss of appetite
- Sometimes nausea, vomiting, or diarrhea (more common in children)
Flu symptoms can vary in severity and may also include sweating, difficulty sleeping, and a general feeling of being very unwell. The flu typically affects not only the respiratory system but the whole body and tends to come on quickly and severely compared to a common cold. People with flu often feel too fatigued to carry on normal activities. If symptoms match these and appear suddenly, it is likely the flu. Diagnosis can be confirmed by a doctor through examination and testing of a sample from the nose or throat. If there is a sudden onset of these symptoms, especially with high fever, muscle aches, and fatigue, it is reasonable to suspect flu. Mild cases may resemble a common cold but flu is usually more severe.
