III: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism

Diseases of the blood and blood-forming organs encompass a variety of distinct conditions that impact the blood and its production. These illnesses can affect blood cells at any stage of development, from the stem cells located in the bone marrow to mature cells circulating in the bloodstream. These conditions may have various causes, such as genetic mutations, exposure to radiation or toxins, viral infections, or disorders of the immune system. Common symptoms may include fatigue, weakness, shortness of breath, excessive bleeding or clotting, or frequent infections due to immune dysregulation. The progression of these illnesses can be acute or chronic and may affect a plethora of systems within the body. Disorders involving the immune mechanism typically result in an overactive or underactive immune response, which can lead to allergies, autoimmune diseases, and immune deficiency disorders respectively.