Hi, I have no known or identifiable cause for either of my two clotting episodes. I do have an autoimmune disease that can increase the risk for clots, but otherwise, I don't know if that specifically facilitated the clots since I was in remission when both clots occurred or if there were other risk factors involved. Sometimes I just think there's just a perfect storm of things happening in your body that can cause a clot. Also, there may things that cause clotting that are still unknown. You'll find a lot of people here and on the DVT board who have idiopathic blood clotting events.

What other tests are you having done?

I also don't know the cause of my clotting. I've had all the tests done two times (and some have been done three times) and I'm negative on everything. My first two DVTs were blamed on birth control, but I wasn't taking that when I got my PEs, so it is hard to know if they played any part at all.

Sometimes, like @rmb said, it really is just a "perfect storm" of events. I read a study at some point, that said up to a third of clotting events can be ideopathic and I think I fall into that category.

I'm kind of in the same situation regarding not knowing why for every time. The first ones were pregnancy/injury related. But I've had other clotting events which don't have terribly clear reasons. One is completely unexplained. The others there were "reasons" physically, but it was stuff that most people don't get clots from.

I've been tested 2-3 times for clotting disorders, and I've always had everything come back negative. My hematologist said that it's still a bit of a shot in the dark, identifying a clotting disorder, even among patients who likely have one. There's just a lot more to be learned about blood and the clotting mechanism, it's one of those things most doctors will admit that science doesn't know enough about yet. So, you not having an easily identifiable cause is, unfortunately, not that uncommon.

I have had some genetic testing done because my doctors don't believe such a minor injury that I had could cause as much as it did with me. However, so far any genetic testing has been negative. I have not had all done yet.. My hemotologist also said that there are a few factors that testing is not available for.

I agree with RMB that sometimes there's just a perfect storm of things that accumulate. I just wish there was some early "storm" warning detection available. :-)