The causes of recurrent fever are complex and the tests performed are numerous, mainly based on history, accompanying symptoms and signs. Usually laboratory tests such as routine blood and urine tests, biochemical tests, bacterial cultures, etc., and imaging tests such as X-rays, CT, ultrasound, etc., as well as histopathological examinations if cancer is suspected and other diseases are difficult to identify. In short, the tests performed will vary from person to person and can be chosen according to the doctor’s recommendations.