Which of the following is a common symptom of influenza?

Fever and chills are hallmark symptoms of influenza, commonly resulting from the body's immune response to the virus. When someone contracts influenza, the immune system works to fight off the infection, which often triggers a febrile response, leading to elevated body temperature. Chills can accompany fever as the body experiences fluctuations in temperature regulation. In addition to fever and chills, influenza symptoms typically include cough, sore throat, body aches, fatigue, and headaches. While other symptoms such as chest pain and severe headache can occasionally occur, they are less characteristic of influenza compared to fever and chills, which are more consistently reported among individuals with the flu. Joint swelling is also not a common symptom associated with influenza, making fever and chills the most central indicators of the illness.