Hi .my cousin is suffering from something that dr. are not sure about . they told her that her rbcs are shrinking.. and her blood is iron deficient?

Small red cells: Red cells are small in iron deficiency. They do not actually shrink, but the new ones that replace the old are smaller -- hence the misunderstanding. It's imperative that the cause of the iron deficiency be identified, and treated if possible. Heavy monthly loss just requires iron supplementation, other iron loss needs full investigation.