Tendinitis of the elbow, also called lateral epicondylitis or "tennis elbow," is an injury that tends to develop over time when repetitive motions such as swinging a tennis racket strain the muscles and put stress on the tendons, states WebMD. Microscopic tissue tears occur as a result.
Symptoms of elbow tendinitis include tenderness or pain in the knob on the outside of the elbow, according to WebMD. This pain may spread throughout the upper or lower arm. Even though the tendinitis is in the elbow joint and surrounding tendons, it may hurt more when the person does something with his hands. The most pain may occur when the person lifts something, grips an object, makes a fist, opens a door, shakes hands, raises his hand or straightens out his wrist.
Playing tennis is one of the ways a person might get elbow tendinitis, hence its common name "tennis elbow," but many everyday arm motions cause this injury as well, explains Mayo Clinic. Possible causes of elbow tendinitis include cutting cooking ingredients, painting or using plumbing tools. Elbow tendinitis is most common in middle-aged people; plumbers and carpenters, who have jobs requiring repetitive wrist and forearm motions; and people who play racket sports.