My mother-in-law has developed blackish marks on her hands and legs. Looks like blood clots. It pains if it is pressed by finger. Why is this happening? Is this serious? She is 49 yrs old. She takes regular medicines for high blood pressure, cholesterol, hypo thyroid. Everything is under control. We are worried about the black marks which has developed over last 1 and half years. We have also asked her Cardiologist regarding this, but the Doctor didn't take it that seriously. So we are confused!