Oxygen, nutrients, and waste, cannot be delivered to the rest of your body.
It depends on where the blockage is, but if a majority of the artery’s or veins are blocked, you might die since the majority of blood can’t get through.
If an artery, especially one near the aorta or blocking many arteries gets blocked, bad things can happen. The arteries being blocked will not be able to let blood through
If blood cannot get through, it cannot be delivered to your organs.
Your organs will not get oxygen, and you might die, if not treated.