Flu generally comes on quickly. Symptoms can include:

• fever or feeling feverish/chills (not everyone will have a fever)
• cough
• sore throat
• runny or stuffy nose
• muscle or body aches
• headaches
• fatigue (tiredness)
• some people may have vomiting and diarrhea

Note that some older adults don’t have typical signs and symptoms of infection. Up to half of frail older adults do not have a fever even when they have a serious infection. A fever is a single body temperature reading of greater than or equal to 100.4°F (38°C).

Last Updated October 2022