The question of whether you can still take Oseltamivir after 6 days of fever is to look for the cause of the fever first. If the fever has been present for 6 days and it is caused by a viral infection or an influenza virus infection, no matter whether it is a common virus or an influenza virus that causes the fever, this kind of patient can take Oseltamivir orally, that is to say, they can take Oseltamivir. Because oseltamivir is an antiviral drug, it is effective for fever caused by viral infections, but if the fever is caused by other causes, such as bacterial infections, chlamydia, mycoplasma infections, or fungal infections, the effect of oral oseltamivir treatment is not obvious in these patients. If the fever is caused by non-infectious diseases, such as autoimmune diseases, systemic lupus erythematosus, dry syndrome, rheumatoid joints, etc., the treatment of oseltamivir is not effective. Therefore, for a fever of 6 days, it is also necessary to give timely and effective treatment according to the cause of the disease.