What Causes Large Bruises In The Waist?

62 year old husband, 190 lbs., 5 ft. 11 in. with Heart disease since he was 46 (when he had open heart surgery) Aneurism, and stint surgery twice,along with several minor surgeries. He takes many medications for heart, blood pressure, thyroid and severe head aches, and vitamins. This morning he had two large bruises on each side of his waist. About the size of a baking spud, about 5x3. He said he had not fallen. Any suggestions. If he bumps his arm or most anywhere he bleeds easily and a lot.