Symptoms begin very suddenly. It usually starts 3 to 6 hours after you have been exposed to the virus and may last up to 1 week. Symptoms most closely associated with the flu include:
- Fever. Temperature may range from 102 and 106 °F.
- Chills
- Headache, muscle ache
- Tiredness (moderate to severe)
- Sore throat. Usually lasts 3-5 days.
- Cough
- Chest pain
- Shortness of breath (breathing becomes difficult)
- Diarrhea and vomiting (more common in children)
- Runny nose or stuffy nose (rare)
Although it is not very common, people with the flu may also get a sinus infection, ear infection, or chronic medical conditions such as asthma and chronic obstructive pulmonary disease may worsen because of the flu.