It thins your blood, causing it to not clot as easily. It's also an anti-inflammatory medicine, inflammation ostensibly taking the role of promoting healing to damaged areas among other things.
So yes, it will technically slow your healing from an open wound, however, if it's already clotted closed and not weeping, you're not doing much to it. If you mean beyond that, then I don't know what you'd specifically be worried about. Just know that in order for your body to do basically anything at all, it needs bloodflow. Fucking with it medicinally may be helpful in some cases, like headaches or aches, but not recommended for sores, wounds, and other types of bleeding.