I have noticed unexplained bruising on my thighs (currently a total of 5 bruises). I have tested with a positive ANA (low positive) and have suffered from muscle pain and fatigue for the past 5 years, with no firm diagnosis. I also have had unexplained blood in my urine, but have had a full work up on my bladder (CT and cystoscopy), with no material findings (my mother also has this). A full CBC run just a few months ago was normal, except for the ANA. I have also tested postive for the Smith antibody and am positive for MTHFR. Is this bruising possibly related to an auto immune condition? Does the MTHFR have an impact? I am not on any medication, but do take a B12 and folic acid daily. I also took a very small dosage for predisone about 4 weeks ago, to help relieve inflammation from a back injury (twisted too much in yoga). Not sure if the predisone could cause bruising so much later?