Hello Good Evening, Welcome to HCM, As you have 13 days fever then, it might be severe blood infection, can be Typhoid or Malaria, should be strictly rule out. You should be hospitalized now and get evaluated and treatment. Following investigations should be done: -Widal (tube) test -CBC -ESR -MP Card test -RFT -LFT -USG whole abdomen and following treatment should be started: Inj. Ceftriaxone, Inj. Ofloxacin, IV fluids, symptomatic and supportive treatment, and most importantly anti malarial treatment if clinician suspect it. Regards, Dr. Naresh Jain.