Recurrent or chronic fever is seen in typhoid, tuberculosis, hepatitis, SLE, rheumatoid arthritis, Polyarteritis nodosa (PAN) and other auto immune disorders, UTI, drug fever
, sinusitis, glandular fever
, otitis media, IBS, HIV, STDs, endocarditis
, parasitic infestations (like malaria), fungal infections, lymphomas and other cancers etc. It can even be diabetes and hyperthyroidism.