7 Reasons You Bruise Easily. You might be a klutz…or one of these surprising factors could be to blame. You expect to see purple when you knock your leg into a table or accidentally elbow the locker room wall while changing at the gym. But bruising that comes from the slightest touch or mystery black and blues that show up with zero explanation can be alarming, not to mention unsightly. Don’t panic—one of these factors is likely the culprit.