This branch of medicine is focused on studying different diseases caused by the immune system. Problems within the immune system can be from failure of the system itself, abnormal behavior of the immune system, or malignant growth. Clinical immunology falls into two categories, immunodeficiency and autoimmunity.
Immunodeficiency occurs when the immune system fails to provide an appropriate response. People suffering from recurrent infections such as bronchitis, sinusitis and pneumonia. Blood testing can be done to confirm a diagnosis. Treatment varies depending on the type of immunodeficiency that is present.