I think I have the flu, also called influenza. Should I see my doctor? Call your healthcare professional if you think you have the flu and you or someone you're caring for is at high risk of serious flu illness, or flu-related complications. Unlike a cold, the flu tends to come on suddenly and makes you feel much worse than a cold., Diagnosis Flu vaccines at Mayo Clinic Mayo Clinic offers flu shots in Arizona, Florida and Minnesota. Learn more about how to get your flu shot at Mayo Clinic. To diagnose the flu, also called influenza, your healthcare professional does a physical exam, looks for symptoms of flu and possibly orders a test that detects flu viruses., Find out the similarities and differences between coronavirus disease 2019 (COVID-19) and the flu (influenza) and learn about ways to prevent getting these diseases., COVID-19 symptoms usually start 2 to 14 days after exposure to SARS-CoV-2. Flu symptoms usually appear about 1 to 4 days after exposure to an influenza virus. COVID-19 can cause more-serious illnesses in some people than can the flu. Also, COVID-19 can cause different complications from those of the flu., Get answers to your flu vaccine questions, including whether the vaccines are effective, what forms are available and what side effects to expect., Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. It is characterized by a sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose. The cough can be severe and can last two or more weeks..