For informational purposes only. Nothing in this article is intended as medical advice of any kind. If you fell you may have a medical problem, seek the advice of a licensed Health Care Professional as soon as possible.
The human shoulder is a marvel of bio-engineering. It is one of the few joints capable of 360° rotation in all axes. But like most human physiology, it is a compromise. The shoulder is made up of the juncture or three bones; the humerus (upper arm), the clavicle (collarbone) and the scapula (shoulder blade). The joint is a ball-and-socket joint which allows for the 360° rotation, but in order to have that mobility, the socket is very shallow. The ball-and-socket joint, also known as the glenohumeral joint is most frequently dislocated joint in the human body, because all it has for stability are the four muscles that make up the rotator cuff group. They are deep muscles situated on, and anchored to the scapula. Shoulder movement depends on the coordinated movement of these, and other muscles, but the rotator cuff muscles are the ones that provide stability to the joint. All-in-all, the shoulder assembly is made up of 3 bones, 4 joints, 30 muscles and tendons, and a fragile, fluid-filled sac called the bursa. The shoulder sacrifices strength and stability for mobility. So it’s little wonder that things don’t always work as planned.
Many things can cause shoulder pain, including injury, referred pain from the neck, herniated discs, pinched nerves, carpel tunnel syndrome, irritated diaphragm, and even a heart attack. But Shoulder pain at night is almost always caused by a rotator cuff problem. The rotator cuff muscle group is made up of the supraspinatus, infraspinatues, teres minor, and subscapularis muscles. They are all anchored on the scapula and attached to the humerus. Each one creates a different kind of movement of the arm.
The most common cause of shoulder pain at night is Rotator Cuff Tendinitis, also known as Impingement Syndrome. It is common in athletes who play sports that require overhead throwing and swinging motions such as baseball, football and tennis. The motions put an abnormal strain on the supraspinatus tendon, causing inflammation and pain. It is also common in adults over 45 years old, because the tendon thins with age and is more easily strained. The symptoms are shoulder pain, especially at night, that does not progress up the neck, or down the arm. The pain is aggravated by reaching overhead, lifting the arm up to the side, or reaching behind. The pain at night is often severe enough to interfere with sleep. Recovery consists of RICE (Rest, Ice, Compression, and Elevation), anti-inflammatory medications, and physical therapy. Night relief can sometimes be achieved by using pillows to support the shoulder and stabilize it during sleep.
Rotator cuff tears are rare in young adults due to the toughness of the rotator cuff tendons, but after age 60, the tendons wear down, and can be torn. This results in a partial, or complete loss of normal function of the affected arm. Recovery is very slow. Mild tears are treated very similar to tendinitis, but severe tears may require surgery. The really bad news is that a lot of orthopedic surgeons reserve surgery for younger patients, severe tears that are diagnosed very early, or very active seniors who are in excellent shape.
Bursitis is an inflammation of the liquid-filled sac (bursa) that cushions the shoulder joint. The onset is usually very sudden, and even the slightest movement of the shoulder is excruciatingly painful. The smoking-gun for bursitis is sharp, localized tenderness when the tip of the shoulder is palpitated (pressed). Mild bursitis can be treated with anti-inflammatory medications and physical therapy, but severe cases almost always require injections of steroids directly into the bursa. The good news is that recovery is complete in most cases.
Shoulder pain, especially at night, can be an indicator of a serious health issue. Anytime you suspect you may have a medical problem, you should see a licensed Medical Practitioner as soon as possible.