I have a hematoma after a knee arthroscopy and its red now after 20 days from the surgery and its covering all my leg is that normal?and how to treat

Time to see your doc: Hematomas after surgery need to be addressed with the ortho who did the procedure. I am sure your ortho wants to you to see him 1-2 weeks after the operation. You are having a problem, so go see him.

Go to see your MD: Go to see you ortho for a follow up. Usually, after arthroscopy you will not have that much of bruising. If you are a bleeder, or have a history of easily bruising and your ortho thinks that the bruise is too much- you likely will be referred to see a hematologist/blood specialist to see if you have underlying bleeding disorder etc.

Hematoma: I would contact your surgeon immediately and have you evaluated for an infection and/or DVT (blood clot); alternatively, make sure that you are not applying ice directly to the skin and that you are not developing reflex sympathetic dystrophy (rsd); finally ensure that you are not having a drug reaction.