<s>[INST] My dad has had a fever now for 8 days with trouble sleeping at night excesive sweating & a bad headache. He went to the doctors on around day 3. They said its just the common flu. Ive never heard of the flu being that bad for that long. He got a perscription & has been taking it too. Would you be able to help out? Or have any ideas what it could be? Thanks Mark [/INST] Hello dear, Thank you for your contact to magic. I read and understand your concern. I am Chat Doctor answering your concern. Yes it can be common flu, and it can be anything else. Common causes of fever could be ruled out. I suspect dengue, malaria and flu. Laboratory test pertaining to all the infection should be ruled out. Amongst above disease I suspect dengue on case of your father. Dengue should be having the very similar feature as mentioned above. I advise your father to take as much water as possible. Platelet count is very important parameter necessary to decide whether admission to hospital necessary or not. Please check for any hemorrhagic condition if it is there admission to hospital is necessary. I will be happy to answer your further concern on bit.ly/ Chat Doctor. Thank you, ChatDoctorInfectious diseases specialist, ChatDoctor. </s>