What Is Tendonitis?

Tendonitis (also spelled tendinitis) is an acute condition where the tendons that connect muscle to bone become inflamed. This inflammation can cause pain, loss of mobility in the tendon, and decreased strength in the muscle to which the tendon is connected.

Tendons are fibrous cords of collagen that serve as flexible anchors to connect muscles to bone, in and around the joints of the body. They come in many shapes and sizes, from small ones which enable the movements of fingers, to larger ones, like the Achilles tendon, which help us stand or walk.

There are many reasons why a tendon can become inflamed and, when it does, it can often be painful. The pain can be felt at the insertion site where the tendon attaches to the bone. It can also be felt where the muscle and tendon connect.

Causes of Tendonitis

While there are hundreds of tendons throughout the body, only a small handful are affected by tendonitis. These tendons tend to have fewer blood vessels servicing them, and the lack of blood supply hinders their ability to heal after injury. The parts of the tendon most impacted by this effect are called the watershed zones where the blood supply is at its weakest.

Direct injury—such as a blow to the tendon—can also cause tendonitis. Inflammatory disorders, such as rheumatoid arthritis and osteoarthritis, can also give rise to both the sudden (acute) and persistent (chronic) inflammations of tendons.

Tendonitis is more commonly seen in people over 40 with the risk and severity of symptoms typically increasing with age.

Common Locations of Tendonitis

Tendonitis can happen almost anywhere on the body where tendons exist and is typically classified by its location. Because the condition is often associated with repetitive movements, we tend to see it in people who perform certain tasks by routine or who engage in specific sports activities. Some of the more common types include:

• Achilles tendonitis, involving the tendon between the calf muscle and heel
• Patellar tendonitis, sometimes referred to as jumper’s knees
• Elbow tendonitis, commonly known as tennis elbow or golfer's elbow
• Biceps tendonitis, typically involving the tendon between the biceps muscle on the arm and its insertion in the shoulder joint.
• Rotator cuff tendonitis, known swimmer’s shoulder
• Wrist tendonitis, sometimes called bowler’s wrist

Symptoms and Diagnosis

Tendonitis is typically characterized by recent appearance of pain and inflammation and should not be confused with tendinosis in which structural signs of tendon degeneration exist. In many cases, the appearance of symptoms will be gradual, often associated with a period of excessive activity and without significant injury. The symptoms may appear gradually and worsen over time.

The most common features of tendonitis include:

• Swelling of the tendon
• Tenderness directly over the tendon
• Pain with the movement of the affected area
• A cracking or grating sensation when the joint is moved
• The appearance of a lump or bulge on the tendon itself
• Stiffness due to swelling

Diagnosis is typically made with based on history and physical examination. If the cause is not clear or there are co-occurring conditions, the doctor may order additional tests. X-rays and magnetic resonance imaging (MRI) can be helpful in assessing for additional causes of symptoms.

Treatment

The treatment of tendonitis involves three elements:

• Initial limitation of movement of the affected tendon
• Reduction of inflammation
• Rehabilitation of the injured tendon, joint, and muscle which includes regaining normal tendon mobility and tolerance to loading.

To achieve this, the injured joint can be immobilized to relieve any pressure on the afflicted tendon. Ice or non-steroidal anti-inflammatory drugs, like ibuprofen, can be used in the initial days to reduce swelling and pain.

In people with recurrent or severe symptoms, corticosteroid injections may be used to provide short- to medium-term relief. Overuse of injections should be avoided as it can weaken the tendon over time and increase the risk of rupture.

Treatment may be supported by physical therapy to manipulate and massage the affected area. Recovery tends to be faster, often with the recovery of the full range of motion.

Maintaining fitness and minimizing sudden changes in activity levels can help lessen the risk of developing tendinitis.

A Word From Verywell

Tendonitis can be a painful condition that limits your ability to engage in your normal work or recreational activities. If you suspect you have tendonitis, check in with your physical therapist and get started on treatment right away.