 [ Symptoms ] what are the systems of the flu is ear ache one [ Disease ] influenza also known as the flu is a contagious respiratory illness caused by flu viruses it can cause mild to severe illness and at times can lead to death the flu is different from a cold the flu usually comes on suddenly people who have the flu often feel some or all of these symptoms • fever* or feeling feverishchills • cough • sore throat • runny or stuffy nose • muscle or body aches • headaches • fatigue tiredness • some people may have vomiting and diarrhea though this is more common in children than adults * it is important to note that not everyone with flu will have a fever most people who get influenza will recover in a few days to less than two weeks but some people will develop complications such as an ear infection as a result of the flu pneumonia bronchitis sinus and ear infections are examples of complications from flu symptoms of flu are body ache fever fatigue sore throat cough etc ear ache can be one the symptoms of flu