Shoulder pain: the rotator cuff, common causes and what to do

Reaching for something, putting on a jacket, sleeping on your side. When your shoulder hurts, even the simplest movements get harder. According to MedlinePlus, the shoulders are the most movable joints in the body, but they can also be unstable, because the ball of the upper arm is larger than the socket that holds it. That’s why they rely on muscles, tendons and ligaments to stay in place.^[1]

What could be causing your pain?

The NHS gives guidance on the likely cause based on how the pain shows up:^[3]

Source: NHS, "Shoulder pain" (2023).^[3] This is general guidance; a professional should make the diagnosis.

The rotator cuff

The rotator cuff is the group of muscles and tendons that stabilizes the shoulder. According to the MedlinePlus medical encyclopedia, its two most common problems are:^[2]

• Tendinitis (impingement syndrome): inflamed tendons and bursa, often from repeated overhead motion, holding the arm in one position for long periods, or always sleeping on the same arm.
• Tears: they can be sudden, after a fall or a jerking lift, or chronic, when tendinitis wears the tendon down over time. They can be partial or complete.

Risk factors

MedlinePlus lists:^[2]

• Overhead sports (tennis, baseball pitching, swimming, weightlifting)
• Overhead work (painting, carpentry)
• Long-term poor posture
• Repetitive positioning, such as computer work
• Aging

Symptoms

• Tendinitis: mild pain when lifting the arm overhead or out to the side, which can progress to night pain, weakness and stiffness.^[2]
• Sudden tear: intense pain, weakness and sometimes a snapping sensation.^[2]
• Chronic tear: develops gradually, and night pain is common.^[2]

Treatment

According to MedlinePlus, the first treatment for many shoulder problems is RICE (rest, ice, compression and elevation), along with exercise and medicines for pain and swelling; surgery is kept for when these don’t help.^[1] For the rotator cuff:^[2]

• Tendinitis is treated with rest, ice, anti-inflammatory medicines, activity changes and physical therapy; sometimes with corticosteroid injections and, in some cases, arthroscopic surgery. It often improves over weeks to months.
• Partial tears may improve with rest and physical therapy; complete tears often need surgical repair.

Home care

The NHS recommends:^[3]

• Keep moving the shoulder gently and stay active; don’t stop using it completely, as that can delay healing.
• Do shoulder exercises for 6 to 8 weeks to keep the pain from coming back.
• Keep your shoulders down and back when standing, and rest your arm on a cushion when sitting.
• Use cold or heat (up to 20 minutes, a few times a day, always wrapped in a towel).
• Avoid whatever makes it worse, improvised strenuous exercise, and slouching.

The NHS says self-care usually takes about 2 weeks to start easing the pain, and that recovery can take 6 months or longer.^[3]

When to see a doctor

Book an appointment if the pain is getting worse or hasn’t improved after 2 weeks, or if it’s very hard to move your arm.^[3] The NHS advises urgent care if you have:^[3]

• Sudden or very severe shoulder pain
• Inability to move your arm
• A changed shape or significant swelling
• Pins and needles that don’t go away, or loss of feeling
• An arm or shoulder that feels hot or cold to the touch
• Pain after an injury or fall
• Severe pain in both shoulders
• Fever or feeling generally unwell

If shoulder pain wakes you at night or keeps you from lifting your arm, an assessment can determine whether it’s the rotator cuff or something else, and which treatment is right for you.