I keep getting large bruises on the back of my left thigh & have for years. I'm a 38 year old white male 6'0 190lbs in good shape. I do have lower back problems(bulging disc) & tend to have a lot of tightness in my left hamstring & tingling & numbness in my entire left leg & toes. I do regular physical therapy for my lower back & see a physician regularly. Any ideas about the bizarre bruising? I was recently checked for clots & it came back negative.