Brief Answer: viral illnesses are the most common cause Detailed Answer: HI, thanks for using healthcare magic Fever , joint and sometimes muscle pain as well are usually indicators of an infection, commonly viral . There are other potential causes as well. (1)There are different types of viral infections that can cause these symptoms such as : (a)flu (this would eventually be associated with cough, sorethroat, headache, eyepain, nasal congestion. The fever can start first) (b)dengue- this is a viral illness spread by mosquito bites that is associated with severe joint and muscle pain along with fever. Also causes headache and eye pain but there would no nasal symptoms, no cough or sorethroat. (c )chikungunya- this is an emerging illness also associated with these symptoms. It is also caused by mosquito bites (d)viral illness such as viral gastroenteritis can also be associated with joint pain but there would be other symptoms such as abdominal pain, nausea, vomiting ,diarrhoea (2) other than infection the causes of fever and joint pain are rheumatoid arthritis, rheumatic fever,lyme disease These are not as common as viral causes. If it is the onset of the flu then the other symptoms would start slowly in a few hours. At this point with only these symptoms , it may be difficult determine the exact diagnosis. Treatment would be the use of paracetamol to reduce the pain and the fever. It would be best to use this instead of advil because some viral illnesses are associated with increased risk of bleeding and the advil would worsen this. In addition to the paracetamol, cool liquids and tepid sponging would also help. If your symptoms worsen, you should consider visiting your doctor for an assessment. I hope this helps, feel free to ask any other questions

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