Dear Friend.Deep Vein Thrombosis
(DVT) can have many reasons, it can be Provoked or Unprovoked.
Check if he has any risk factors like, hypertension
, obesity, smoker, on any particular drugs, a long hault travel in bus or plane, bed ridden.
If not, he has unprovoked episode that requires detailed evaluation , your doctor must be evaluating him for that.
For treatment purpose, he must be receiving anti-coagulation. That will followed by long term anti-coagulation, duration depending on the cause of DVT, whether provoked or unprovoked.
Keep him admitted, prompt treatment is required as a clot can reach to lungs, leading to pulmonary embolism
, which can prove to be fatal.
Let us know,if you have any other query.
Wish your friend a speedy recovery.