Your health professional can usually determine if you have tennis elbow by talking to you about the history of your symptoms, daily activities, and past injuries. You'll have a physical exam as well.

X-rays aren't usually needed for diagnosis of tennis elbow but can sometimes rule out other causes of elbow pain, such as arthritis, signs of another type of injury, or a buildup of calcium crystals in a tendon or ligament. X-rays can show unusual bone structure that might cause soft-tissue damage (such as to tendons or muscles), but they don't show soft tissues very clearly. If your elbow pain isn't severe and can't be linked to a specific injury, your health professional may recommend starting treatment without doing X-rays to see whether the problem clears up in a few weeks.

If nonsurgical treatment (such as rest, the use of ice and anti-inflammatory drugs, rehabilitation exercises, and changing or stopping certain activities) hasn't helped relieve elbow pain, or if the diagnosis is unclear, other tests may be helpful.

• Magnetic resonance imaging (MRI) can show problems in soft tissues such as tendons and muscles.
• Arthroscopy allows the health professional to see inside the elbow and get information that can be used together with information from X-rays or a physical exam. (Doctors can surgically treat tennis elbow with arthroscopy.)
• Bone scans are done in rare cases. They can show stress fractures in the bone or certain disease conditions, such as a tumor or infection.
• Arthrogram (Joint X-ray) is an imaging technology that involves injecting a material into the joint to enhance its X-ray image. It shows the bones and soft tissues inside the joint, such as the cartilage. Since MRI has become more available, arthrography is used less often to enhance X-rays.

If your health professional suspects nerve damage, electromyogram and nerve conduction tests can check how well your nerves are working.