Hi.. am 35 yrs old female with hypo thyroidism.i...

What is the definition of fever of unknown origin?
It is the body temperature above 38.2 ° C as a result of the increase in white blood cells or the stimulation of the heat center in the brain
And it lasts for 3 weeks without treatment, or for a week in the hospital
What are the causes of fever of unknown origin?
Infections, including: (otitis media, tonsillitis), and other types of multiple infections.
Taking medication to treat an illness; This causes side effects, such as feverish feeling.
Viral infection, or infection with germs of any type.
Rheumatic diseases such as rheumatoid arthritis, lupus erythematosus, and Behçet's disease
Gout
Mediterranean fever
Inflammation of blood vessels
Thyroid problems like yours
What are the necessary tests done to find out the reason?
A complete blood test, mucosal examination,TSH , and bacterial culture, in addition to a clinical examination, chest x-ray, urine analysis and ESR test.
What are the danger signs that should not be ignored?
Confusion, extreme drowsiness, pain in the neck, stiff neck, rash, difficulty breathing,  spots on the skin, hallucinations, confusion, and convulsions
What is the advice in your case?
You can take Paracetamol 500mg tablets every 6-8 hours for two continuous days, do previous examinations and make sure your thyroid hormone level is whithin normal range , and review an internist.