D70-D77: Other diseases of blood and blood-forming organs

D72: Other disorders of white blood cells

The medical conditions that fall under the category of "Other disorders of white blood cells" generally concern issues in the count, function or form of white blood cells, the immune system’s primary defense against infections and diseases. Conditions within this category can range from absolute neutropenia, where the body has an abnormal or dangerously low number of neutrophils (a type of white blood cell), to eosinophilia, characterized by an excessive quantity of eosinophils, another variety of white blood cell. These disorders can arise due to various causes such as an underlying illness, side effects of certain medications, inherited conditions, or an immune response. Symptoms that may point to a disorder of white blood cells include unexplained fever, frequent infections, fatigue and unexplained weight loss. Progression of these diseases can impact various systems of the body and result in serious health complications over time.