Understanding Rotator Cuff Tendonitis

Front view of shoulder joint with muscles.Tendons are tough tissues that connect muscles to bone. A group of 4 muscles and their tendons form a “cuff” around the head of the upper arm bone. This is called the rotator cuff. It connects the upper arm to the shoulder blade. It gives the shoulder joint stability and strength.

If tendons are injured or strained, they may become irritated and swollen (inflamed). This is called tendonitis. Rotator cuff tendonitis may cause shoulder pain and loss of function.

What causes rotator cuff tendonitis?

Tendonitis results when the rotator cuff tendons are injured or overworked. The most common cause of injury is repetitive overhead activities. These can be work-related activities such as reaching, pushing, or lifting. Or they can be sports-related activities such as throwing, swimming, or lifting weights.

Symptoms of rotator cuff tendonitis

Pain on the side of the upper arm is the most common symptom. Pain may get worse with overhead movements or when you raise the arm above shoulder level. It may also hurt to lie on the shoulder at night.

Treatment for rotator cuff tendonitis

Treatment may include the following:

  • Active rest. This lets the rotator cuff heal. Active rest means using your arm and shoulder, but avoiding activities that cause pain, such as reaching overhead or sleeping on the shoulder.

  • Cold packs. Putting ice packs on the shoulder helps reduce swelling and relieve pain.

  • Pain medicines. Prescription or over-the-counter pain medicines can help relieve pain and swelling.

  • Arm and shoulder exercises. These help keep the shoulder joint mobile as it heals. They also help improve the strength of muscles around the joint.

Possible complications

It might be tempting to stop using your shoulder completely to avoid pain. But doing so may lead to a condition called “frozen shoulder.” To help prevent this, following instructions you are given for active rest and for doing exercises to help your shoulder heal.

When to call your healthcare provider

Call your healthcare provider right away if you have any of these:

  • Fever of 100.4°F (38°C) or higher, or as directed

  • Symptoms that don’t get better, or get worse

  • New symptoms