The elbow is the joint where three long bones meet in the middle portion of the arm. The bone of the upper arm (humerus) meets the inner bone of the forearm (ulna) and the outer bone of the forearm (radius) to form a hinge joint.
The outer bone of the elbow is referred to as the lateral epicondyle and is a part of the humerus bone. Tendons are attached to this area which can be injured, causing inflammation or tendinitis (lateral epicondylitis, or "tennis elbow").
The inner portion of the elbow is a bony prominence called the medial epicondyle.
Additional tendons from the muscles attach here and can be injured, causing medial epicondylitis, "golfer's elbow."
A fluid-filled sac (bursa), which serves to reduce friction, overlies the tip of the elbow (olecranon bursa). The elbow can be affected by inflammation of the tendons or the bursae (plural for bursa) or conditions that affect the bones and joints, such as fractures, arthritis, or nerve irritation.
You need to go to an orthopedician for proper diagnosis and treatment. Stop your weights till you diagnose the case.