What's that shoulder sound?

It catches you off guard: a sudden crunch, pop, or click from your shoulder that you've never heard before. Is your shoulder sounding an alarm? Is it just normal aging? The answer depends on a number of factors.

About the shoulder

The shoulder is made up of three bones (the upper arm bone, collarbone, and shoulder blade) and many soft tissues (including muscles, ligaments, and tendons).

Within the shoulder are four joints. The main joint has a ball-and-socket construction: the top of the upper arm bone is the "ball" that fits into a shallow "socket" in the shoulder blade.

Aging, bone growths, and injuries can cause changes to the shoulder that generate sounds from time to time.

Sounds fishy

There's no one sound unique to a particular shoulder problem. That makes it hard to know what various shoulder noises are telling you. Here are some possibilities.

Arthritis. When cartilage that cushions the shoulder joints wears away, the bones can rub against each other. "Or sometimes the cartilage frays as it wears out, like pilling on a sweater. As the ball glides against it, it makes noise," says Dr. Jason Simon, an orthopedic surgeon with Harvard-affiliated Newton-Wellesley Hospital. Arthritis can be accompanied by stiffness and pain.

Bone breaks. Broken bones can rub against each other audibly. Breaks are accompanied by pain, swelling, discoloration, and stiffness.

Rotator cuff tears. The rotator cuff is made up of tendons that help you raise and rotate your arm. The tendons also help keep the ball centered in the socket. "If you have a tear in a tendon, the ball can move abnormally, or there could be loose tissue that gets caught as you move your arm. Both make noise," says Dr. Simon. Tears are accompanied by pain that gets worse with shoulder use.

Gas bubbles. When you move your shoulder, it can release gas that has built up in a bubble in the joint. It doesn't hurt; the release is similar to cracking your knuckles.

Bone spurs. Sometimes calcified growths develop in the shoulder. "The most common bone spur can rub against the rotator cuff. This can result in noises or pain, particularly with overhead motion," says Dr. Simon.

Neck problems. In some cases, what you perceive as a shoulder sound may actually originate in the neck. For example, it may come from neck bones that rub together due to worn cartilage. This might or might not hurt.

Bursitis. The shoulder joint contains a number of small fluid-filled sacs (bursae) that protect tendons from the bones and ligaments they glide over. "When a bursa is swollen or inflamed, it gets compressed as the joint moves, which creates a sound," Dr. Simon explains.

Loose parts. You might not feel tiny pieces of debris in your shoulder — such as bits of cartilage that have broken off or detached stitches from past shoulder surgeries — but they can make noise as they move within the joint.

What you should do

Dr. Simon recommends investigating shoulder noises if you have shoulder pain, weakness, or limited movement, or if the sound followed a shoulder injury. He says it's also smart — though not urgent — to ask your doctor about shoulder sounds that aren't accompanied by other symptoms: "It's always better to be safe and catch something before it gets worse and we can't fix it."

Seek help first from your primary care doctor, who may refer you to an orthopedic surgeon. To make a diagnosis, the doctor will conduct a physical exam and order imaging tests, such as x-ray or MRI.

Treatment, if necessary, doesn't automatically mean surgery. Some conditions need only physical therapy or anti-inflammatory medications or injections. "If there's something torn, broken, or completely worn out, we may consider surgery. But that's a last resort," says Dr. Simon. "Shoulder noise doesn't mean there's an operation in your future."

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