What are tendonitis and tenosynovitis?

Tendons are strong cords of tissue that connect muscles to bones. When a tendon is inflamed, it's called tendonitis. It can happen to any tendon in the body. An inflamed tendon can cause swelling, pain, and discomfort. 

Another problem called tenosynovitis is linked to tendonitis. This is the inflammation of the lining of the tendon sheath around a tendon. Often the sheath itself is inflamed, but both the sheath and the tendon can be inflamed at the same time.

Common types of these tendon problems include:

• Lateral epicondylitis. This is most often known as tennis elbow. It causes pain to the side of the elbow and forearm, along the thumb side of the arm. The pain is caused by damage to the tendons that bend the wrist back and away from the palm.

• Medial epicondylitis. This is most often known as golfer's or baseball elbow. It causes pain from the elbow to the wrist on the palm side of the forearm. The pain is caused by damage to the tendons that bend the wrist toward the palm.

• Rotator cuff tendonitis. This is a shoulder disorder. It causes inflammation of the shoulder capsule and related tendons.

• DeQuervain tenosynovitis. This is a common tenosynovitis disorder. It causes swelling in the tendon sheath of the tendons of the thumb.

• Trigger finger or trigger thumb. This is a type of tenosynovitis. The tendon sheath becomes inflamed and thickened. This makes it hard to extend or flex the finger or thumb. The finger or thumb may lock or "trigger" suddenly.

What causes tendonitis and tenosynovitis?

The cause of tendonitis and tenosynovitis is often not known. They may be caused by strain, overuse, injury, or too much exercise. They may also be linked to a disease, such as diabetes, rheumatoid arthritis, or infection.

What are the symptoms of tendonitis and tenosynovitis?

Symptoms may include:

• Pain in the tendon when moved

• Swelling from fluid and inflammation

• A grating feeling when moving the joint

The symptoms of tendonitis can seem like other health problems. Talk with your healthcare provider for a diagnosis.

How are tendonitis and tenosynovitis diagnosed?

Your healthcare provider will ask about your health history and give you a physical exam. You may have tests to check for other problems that may be causing your symptoms. The tests may include:

• Joint aspiration. The healthcare provider uses a needle to take a small amount of fluid from the joint. The fluid is tested to check for gout or signs of an infection.

• X-ray. A small amount of radiation is used to make an image. Tendons can’t be seen on an X-ray, but they can show bone. This test can check for arthritis, calcifications, and other problems.

How are tendonitis and tenosynovitis treated?

Treatment may include:

• Changing your activities

• Icing the area to reduce inflammation and pain. To make a cold pack, put ice cubes in a plastic bag that seals at the top. Wrap the bag in a clean, thin towel or cloth.

• Putting a splint on the area to limit movement

• Getting steroid injections to reduce inflammation and pain

• Taking nonsteroidal anti-inflammatory drugs (called NSAIDs) to reduce inflammation and pain

• Taking antibiotics if due to infection

• Having surgery if other treatments don't work

Key points about tendonitis and tenosynovitis

• Tendonitis is when a tendon is inflamed. It can cause swelling, pain, and discomfort.

• Another problem called tenosynovitis is linked to tendonitis. This is the inflammation of the lining of the tendon sheath around a tendon.

• Common types of tendon problems include rotator cuff tendonitis and trigger finger or trigger thumb.

• Tendonitis can be caused by strain, overuse, injury, and too much exercise.

• Treatment may include changing your activities, icing the area to reduce pain, and using a splint to limit movement.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new directions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions.