A headache is a primary sign of anemia. Those are regular painful feelings in the head which range in their severity. In addition to harsh headaches, anemic patients may feel lightheaded or dizzy. It often occurs when the person is moving too fast (for instance, getting up immediately after laying for a while). Then, he or she can see black spots in front of eyes. It all happens when the organism lacks oxygen which must reach the brain via the red blood cells.