Blood Diseases.

http://en.wikipedia.org/wiki/Red_blood_cell

• Anemias (or anaemias) are diseases characterized by low oxygen transport capacity of the blood, because of low red cell count or some abnormality of the red blood cells or the hemoglobin.

• Iron deficiency anemia is the most common anemia; it occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed

• Sickle-cell disease is a genetic disease that results in abnormal hemoglobin molecules. When these release their oxygen load in the tissues, they become insoluble, leading to mis-shaped red blood cells. These sickle shaped red cells are less deformable and viscoelastic meaning that they have become rigid and can cause blood vessel blockage, pain, strokes, and other tissue damage.

• Thalassemia is a genetic disease that results in the production of an abnormal ratio of hemoglobin subunits.

• Hereditary spherocytosis syndromes are a group of inherited disorders characterized by defects in the red blood cell's cell membrane, causing the cells to be small, sphere-shaped, and fragile instead of donut-shaped and flexible. These abnormal red blood cells are destroyed by the spleen. Several other hereditary disorders of the red blood cell membrane are known.

• Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B₁₂ from food. Vitamin B₁₂ is needed for the production of hemoglobin.

• Aplastic anemia is caused by the inability of the bone marrow to produce blood cells.