An immunoglobulin test is ordered if a person gets some symptoms of the immunoglobulin deficiency, like recurrent infections, particularly related to the respiratory tracts like lungs or sinus. A person also turns into an ideal candidate if he suffers from some issues in the digestive system like intestines or stomach or chronic diarrhea. An immunoglobulin test is ordered if a person has got some signs of chronic infection or chronic inflammation and when some healthcare practitioner guesses abnormal or excessive production of immunoglobulin. This test is ordered periodically for monitoring the course of the condition of a person. This test might be performed on CSF or cerebrospinal fluid when a healthcare practitioner thinks that a condition that is affecting a person’s CNS (central nervous system) is linked with excessive production of immunoglobulin.