D80-D89: Certain disorders involving the immune mechanism

D80-D89 refers to a group of disorders involving the immune mechanism. This includes conditions where the body's immune system, which normally functions to defend against pathogens, is impaired or dysfunctional. These disorders compromise the body's ability to fight off infections, leading to an increased susceptibility to diseases caused by various germs. Symptoms can vary greatly depending upon the specific disorder and the severity of the immune deficiency but can include recurrent infections, prolonged illnesses, and poor response to treatment. These disorders can either be genetic, meaning they are inherited from the parents, or can be acquired later in life as a result of other medical conditions, environmental factors, or treatments such as chemotherapy. Further, these conditions can affect several bodily systems, with the hematological system (related to blood) often being primarily impacted. Disease progression also differs based on the specific condition, with some disorders leading to a steady decline in health over time.