Pulmonary Embolism Support Group
By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death.
I do know that altitude can be a bit more of a challenge if you're recently diagnosed. I live in Denver and frequently travel into the mountains and my stamina at 8000 or so feet was not that good for a while after my PEs. I'm good now, though, and have even done some hiking up that high in the middle of winter in sub-freezing temps. Took a little while to get there, but totally worth it.
I'm homozygous( 2 copies) FVL, and traveled and camped at all sorts of altitudes before I was ever aware I had FVL, without any problems. My clotting episode came after a very long drive. Also, obviously since I have two copies, my parent's must have had at least one copy each. They lived at about 5,000 ft for the last 30 years of their life. My mom had two DVTs,( the first one after surgery at age 74, and another at age 83). My dad had a superficial clot, just once in his 70's. So there's a lot of interplay between genes and risk factors.
One thing you can do to help yourself at higher altitudes, is to hydrate, hydrate hydrate! It's also good that you're checking in with your hematologist since he/she can best evaluate your personal risk factors.