Im having a constant pain on a thigh and knee for over a year and i font know whats causes the pain?

Keep pain diary: Pain Diary Keep a diary that notes: When did it start? Where does the pain start and go to? How long does it last? When (Time of Day) does it happen? What brings it on? What makes it worse? What makes it better? This will likely tell you and your dr what it is that is paining you. Share with your team. They know you. We do not.