Anemia Support Group
Anemia (or anaemia), which literally means "without blood," is a deficiency of red blood cells and/or hemoglobin. This results in a reduced ability of blood to transfer oxygen to the tissues, and this causes hypoxia; since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences.
It can be classified in a variety of ways, based on the morphology of RBCs, underlying etiologic mechanisms, and discernible clinical spectra, to mention a few
The three main classes include excessive blood loss (acutely such as a hemorrhage or chronically through low-volume loss), excessive blood cell destruction (hemolysis) or deficient red blood cell production (ineffective hematopoiesis).
The above was referenced via Wikipedia, I would suggest you google search anemia, and symptoms of to help assist you in finding the answer to your specific question.
And by the way, worrying about it serves no useful purpose whatsoever, so simply stop doing so.