I have had microscopic hematuria ever since I went thru menopause. I have had every test in the books trying to find a cause – there is none. I was told that since my estrogen levels are to the point of being non-existent, this causes the tissue to thin and allows traces of blood to leak thru the fragile tissue. It is quite common in menopause and post menopause. My urologist recommended topical estrogen cream which is quite safe because all it does is replenish the tissue locally which helps with recurrent UTI. Hope this helps.