How many types of anemia are there? are they divided in to groups? if so, how many and what are the names of the groups?

Complicated question: Most common is iron deficiency. That comes from blood loss another common type is anemia of chronic disease. Where your kidneys (for instance) don't produce erythropoetin. Another general type is hemolytic anemia. Blood is cleaved up. Most common cause in someone of your age group would be iron deficiency from menses. It's a huge question. Sorry this forum doesn't allow for bigger answers.