It's not always second to something else. My mother has had that for at least 30 or 40 years and that's all she has. About 20 yrs ago it started happening to me and really freaked me out. It would happen to a couple of fingers at a time, toes and sometimes my nose. I worried myself almost to death about it and of course after googling it I was pretty sure I was dying. I don't know if you're a smoker, but I was. I finally quit smoking a couple of years later and within a year it quit completely. It has to do with blood flow and apparently mine was restricted due to the 2 packs of cigs I was smoking daily. Maybe you could try taking a baby aspirin daily and see if that helps. Good luck and don't read more into it than there is.
