My father had blood tests. hemoglobin and red blood cell counts low but ferritin, iron, b12 normal. doctor said he has anemia. treatment?

Find the cause: There are over 100 different causes of anemia. Dad has a bleeding stomach or colon cancer until proved otherwise; yes, iron and ferritin can be normal early-on when this is happening. History and physical, reticulocyte count, stool guaiac, a look at the peripheral blood smear by someone who's good at it comes next. Glad you're there for Dad.