Symptoms include fever, cough, sore throat, body aches, headache, chills, and fatigue. In some cases vomiting, diarrhoea, dyspnea and myalgia(muscle pain). Swine flu is diagnosed by virus isolation or by detection of viral antigen, viral RNA or specific antibody. To diagnose H1N1, a respiratiry specimen would generally need to be collected within the first 4 to 5 days of illness. common cold and flu can also associated with all these symptoms, so only a lab analysis can identify whether it is swine flu or not.