Influenza (J11.1))

Influenza symptoms abruptly appear after an incubation period of 1 to 2 days. Fever, chills, headache, malaise, myalgia, and loss of appetite are symptoms commonly seen. Respiratory symptoms can also appear with influenza which can include a dry cough, nasal congestion, clear nasal drainage, and sore throat. Fever will often rapidly increase between 100o F to 104o F within 12 hours of onset of symptoms. The fever will usually start to decline by the second or third day but has the potential to last four to eight days. Once the febrile stage has passed the patient will have a convalescent phase for about 2 weeks after, which includes a cough and feelings of malaise and fatigue (Buttaro et al., 2013).