What Causes Prolonged Fever?
A number of causes according to the symptoms
Detailed Answer:
Dear Ms, I have gone through your question and I understand your concerns but prolonged fever more than 3 weeks can be due to a number of causes such as:
1) abdominal or pelvic abscess which can be excluded by ultrasound
2) endocarditis which should be accompanied by chest pain
3) tuberculosis which should be accompanied by night sweats and bloody cough
4) urinary tract infection which can be excluded by a urine analysis
5) cytomegalovirus or EB virus infection
6) systemic lupus erythematosus which can be diagnosed anti-ds-DNA
7) chron's disease which should be accompanied by diarrhea
I hope I answered your question. Let me know if I could assist you further.
Regards