Hello yes i have a bad cough, headache and sore throat and body feels extremely tired. what can be causing this?

Flu? Other virus?: These symptoms are typical for influenza, especially if there is fever, but also for many other viruses -- maybe just a bad cold. Pneumonia is possible. There's no way to know for sure without professional evaluation. Contact your doctor ASAP; treatment can be given to speed recovery from flu, or an antibiotic may be recommended if it's bronchitis or pneumonia. Good luck.