What Do Reappearing Bruises On Inside Of Left Leg Suggest?

Hi, I have been having a reoccurring fairly good sized bruise on the inside of my left leg for quite a while now. It will heal and then I will wake up the next morning and another bruise in the same place has replaced it. I have not been injured or been bumping the inside of my left leg. I have also been extremely tired even though I have been getting enough rest.