As per your history, it seems you had a deep venous thrombosis and presently you are on blood thinners. In a lot of patients, at times pain ,numbness and heaviness, skin darkening develops later after the formation of clot.. the clinical entity is called as Post thrombotic syndrome. The severity can be judged by a simple scoring system called as Villalta score( can be accessed online). I would suggest you calculate your score and if it is high, consult your vascular specialist or a hematologist. By the time, you can use some conservative therapies as below 1. Use skin emollients and moisturisers 2. start graded physical activity 3. compression stockings 4. Ice packs Thanks