Hi,
As you stated, medicine has made remarkable advances in the past few years but unfortunately, in some persons, the exact cause of their condition is never know. This is one of the reasons the term idiopathic (cause not known), is included as a possible diagnosis in some persons.
With regard to
blood clots, there is a triad called virchow triad, looking at the cause of clots. According to this triad, clotting is due to one or more of these:
(1) persons has blood that clots easily- hypercoagulability-- blood clotting disorder
(2) damage to the blood vessels- this increases the risk of a clot occurring
(3) stasis (slow) or turbulent blood flow
Your doctors may have checked the lower
limbs to see if there was a possibility of a clot forming in the legs (DVT) and going to the lungs, this would be stasis.
Polycythemia (thick blood),
dehydration, immobility,
heart failure. It can also cause stasis to occur. They may also have done blood tests to see if a clotting disorder was present. Previous surgery, cancer affecting stasis and blood clotting, inheritance /genetic, side effect of medication are also other possible causes.
I hope this helps. Let me know if I can assist you further.
Regards,
Dr. Michelle Gibson James