Shoulders could be considered the Jack–of–all–trades joints. Our shoulders carry blame, responsibility and the weight of the world. We put our "shoulders to the wheel," "stand shoulder to shoulder" with others or "turn a cold shoulder." We cry on shoulders and slap them in congratulations. Clearly, our shoulders serve us remarkably well—and not just metaphorically.

In fact, the shoulder is one of the most mobile joints in the body. The interplay of bones, muscles, cartilage, tendons and ligaments in the shoulder allows us to lift, push, pull and rotate our arm in a complete circle, so we can do things like serve a tennis ball or swim or crawl.

Three bones form the foundation of the shoulder—the upper arm bone, the shoulder blade and the collarbone. The upper arm bone fits into a socket called the glenoid, a somewhat flat socket that differentiates the shoulder from a ball–and–socket joint like the hip.

Instead, the shoulder depends on soft tissues to hold it in place, which accounts for its vulnerability to injury.

Causes of shoulder pain

Many shoulder problems arise from the simple wear and tear of living. Most people over age 50 will experience at least some degree of shoulder deterioration.

You can help prevent shoulder injuries by keeping supporting tissues strong and supple with regular upper body exercise like swimming, resistance workouts with weights or bands, and stretching.

Overuse—putting more stress on the joint than it can handle—is a leading cause of sudden shoulder pain. Trying to lift or move a heavy object is a leading cause of should injury.

What to do if your shoulder hurts

If your shoulder hurts, don't ignore the pain. Pain is your body's way of telling you to stop and pay attention.

Shoulder pain usually is a sign of inflammation or tears in the tissues supporting the joint. The rotator cuff, which is composed of four muscles that stabilize the shoulder joint, is particularly prone to injury. However, most shoulder problems will heal within a week or two with proper care.

If you hear a popping or cracking sound when you injure your shoulder, go straight to the doctor—don't just shrug it off. For less serious injuries, ice your achy shoulder for 20 minutes two or three times a day. Rest and take anti–inflammatories to reduce inflammation.

If you've treated your achy shoulder for a week or so with no results, make an appointment with your doctor.

Treatments for shoulder pain

If you are having persistent shoulder pain, your doctor will check the arm's range of motion and may advise physical therapy, anti–inflammatories and possibly a cortisone injection to allow the joint to move more smoothly.

If the injury appears more serious, the doctor may order an MRI to determine if there are tears in the rotator cuff, and whether the tears are partial or complete. Rotator cuff injuries usually are treated with physical therapy, but severe tears may require surgical repair. Other shoulder problems include:

  • Frozen shoulder – No one knows exactly what causes this condition, which typically affects women 40 to 60 years old. The shoulder capsule becomes inflamed and contracts, severely limiting the shoulder's range of motion. Most cases resolve within six to nine months with a physical therapy program of exercise and stretching, anti–inflammatories and possibly an injection. Without treatment, the condition can take up to 18 months to resolve. Severe cases may require surgery.
  • Arthritis – Though less common than in other joints like the knees and hips, arthritis can cause shoulders to feel stiff and painful and make noises when moved. For people with arthritis, shoulder replacement surgery can bring welcome relief, though it's much less common than knee or hip joint replacements.

Shoulder replacement surgery may also be used with people who have badly fractured a shoulder in a fall or accident.

There have been many advances in shoulder replacement surgery in recent years. Options range from a total shoulder arthroplasty to replace both the ball and socket joint to replacing only the ball at the end of the humerus. Reverse shoulder arthroplasty is another option. This procedure reverses the natural anatomy of your shoulder by putting the ball where the socket is and the socket where the ball was located.

If your shoulder starts to twinge, stop what you're doing and give it a chance to rest and recuperate. Pushing on through the pain will make the injury worse. You've got a good head on your shoulders, so use it.