What are the differences between macrocytic anemia and microcytic anemia?

What are the differences between macrocytic anemia and microcytic anemia? 

Anemia is a term for low hemoglobin or red blood cells. Anemia can be divided into different types based on the volume of the red blood cells. Macrocytic anemia means that the red blood cells are larger than normal. In microcytic anemia, the cells are smaller than normal. We use this classification because it helps us to determine the cause of the anemia.

The most common causes of macrocytic anemia are vitamin B-12 and folate deficiency. Pernicious anemia is a type of macrocytic anemia due to the body not being able to absorb vitamin B-12. Elderly, vegans, and alcoholics are more susceptible to developing macrocytic anemia.

The most common cause of microcytic anemia is iron-deficiency anemia, usually due to poor dietary intake or blood loss, such as menstrual blood loss or through the gastrointestinal tract. Pregnancy, menstruating women, infants, and those with a diet low in iron may have an increased chance of developing microcytic anemia. Other causes of microcytic anemia include defects in hemoglobin production such as sickle cell disease, thalassemia, and sideroblastic anemia.