Some of the main symptoms of flu include: a high temperature (fever) of 38C (100.4F) or above tiredness and weakness a headache general aches and pains a dry, chesty cough Cold-like symptoms, such as a blocked or runny nose, sneezing, and a sore throat, can also be caused by flu, but they tend to be less severe than the other symptoms you have. Flu can make you feel so exhausted and unwell that you have to stay in bed and rest until you feel better.