My Dad Fell And Hurt His Elbow, It Is Swollen

My dad fell and hurt his elbow, it is swollen at the tip of his elbow and his forearm is also swollen. In addition to that it is red in those same places and warm. He won't go to see a doctor and it has been about 4 days since he has done it. Swelling has gone down some but it is still red. Im worried that is infected. How serious is this situation. He is fighting going to get it checked out.