Why is my cbc - rdw high? what health risks does this pose in the future?

Cells are dividing: Rdw is a measure of the cell width or size, and if you have a high RDW it usually means that you have many more immature cells -- and so that means you have cells that are more immature than usual. A rbc RDW means the red cells are slightly larger.

Often nothing: Lab reference ranges are set to that a few percent of healthies fall outside on either end. RDW does tend to rise as the body becomes depleted of iron, before anemia develops. If this could be you (frequent blood donor, heavy periods, vegetarian), it may be a red flag. If there's a more worrisome cause, it will be clear from the look of the peripheral smear. Best wishes.