Hi, when i straighten my arms, my elbows click and numbness. tendonitus or arthritus? possibility

Varies: There is a term called crepitance, which is where a joint can click and pop secondary to early arthritic conditions. But there are also tendon and ligent conditions that can cause clicking in the elbow as well. Finally, numbness suggests at least some neurological involvement. Don't hesitate to be seen and a detailed exam and appropriate studies will usually give you a definitive diagnosis.