The proper name of “Tennis elbow” is lateral epicondylitis. It is an inflammatory condition of the common extensor muscles tendon that is caused by wear & tear or injury. It’s more commonly seen in the dominant arm and affects middle age individuals most commonly. And as the name suggest, it’s rather common in the regular tennis players who play > 2 hours per week.
There is usually not much pain at rest but the severe pain will be triggered by certain “particular” movements in the elbow, such as opening a door knob or a jar and it will “catch” and result in severe pain in the affected elbow.
Tennis elbow is actually the “sister” of Golfer’s elbow, and it is almost ten times as common. Golfer’s elbow is the essentially the same pathology, but happening at the inner aspect of the elbow (near the funny bone), caused by the inflammation and degeneration of the common flexor muscles tendon. Other causes of elbow pain such as nerve impingement syndrome, or any other bone or joint pathology.