Final answer:
Anemia is a condition where the blood's capacity to carry oxygen is diminished due to causes like excessive bleeding, genetic disorders, or nutritional deficiencies. It often results in symptoms like weakness and fatigue. Aplastic anemia is a form with insufficient RBC stem cells.
Step-by-step explanation:
Anemia is a condition in which the oxygen-carrying capacity of blood is reduced. This can be due to a variety of causes such as excessive bleeding, inherited disorders like sickle cell anemia or thalassemia, or nutritional deficiencies including a lack of iron, folate, or vitamin B12. Disorders like sickle cell anemia result in crescent-shaped red blood cells that cannot effectively pass through capillaries, causing pain and decreased oxygen delivery. Thalassemia involves a defect in hemoglobin subunits, leading to red blood cells with insufficient hemoglobin levels.
Anemias related to decreased or faulty red blood cell (RBC) production, such as iron deficiency anemia or diseases of the bone marrow and stem cells, also diminish blood's oxygen transport capabilities. In some cases, anemia may be symptomless, but it often results in general weakness, fatigue, shortness of breath during activity, or poor concentration.
Aplastic anemia is a specific type where the numbers of RBC stem cells are deficient, sometimes inherited or triggered by factors such as radiation or chemotherapy.