What cause so many bruise I am getting brusise all over me for n o reason.

Clotting problem? Certain medications such as Aspirin and Coumadin (warfarin) can cause you to bruise easily. However, illnesses that interference with platelet function can do the same thing. If you are not taking a medication that is known to cause easy bruising, you should have a full blood work up by your medical doctor as soon as possible to help find the cause.
Thin skin or meds. Usually the bruises are due to being on aspirin, or blood thinners (coumadin (warfarin) or such meds), or having very fragile skin/blood vessels.